So, if you're a 3.5 character above about level 8, you're expected to be wearing enough magic items to fill pretty much all of your item spaces with neat effects. That's great and all, but what about characters who aren't allowed to use magic items, such as many of the classes I've made? Well, I have good news for you, because here are some mundane items that fill those slots!

You can't wear more than one mundane item in each slot. Or rather, you probably can, but they'll interfere with each other and you won't benefit from either (have you ever tried wielding two bladed rings on the same finger?). If you try to wear a mundane and a magical piece of equipment in the same slot, the magical one will work, but the mundane one won't, because the magical one gets in the way (have you ever tried wielding a bladed ring while wearing a magic ring on the same finger?).

Mundane items don't resize to fit the wearer, and generally cannot be used if they don't fit. Some, such as a false blindfold, are less picky about the size of the wielder as their own size is mutable (e.g. by folding the blindfold). Others are not. Which is the case is essentially a matter of common sense.

All these items are always masterwork, usually meaning that you get a +1 enhancement bonus to attack rolls with them, their armour check penalty is reduced by 1 and they grant a +2 bonus to any relevant skill check using them.

Head Slot

Amplifying Mask
This mask contains a primitive megaphone, amplifying the speaker's voice so that it can be heard at about ten times the usual distance. By screaming or bellowing at the top of their voice as a standard action, the creature wearing the mask can deal sonic damage in a 30 foot cone: 1d6 to each creature in the cone, plus 1d6 to each creature within 20 feet, then 1d6 to each creature within 10 feet, then another 2d6 to each creature within 5 feet. A creature who takes damage must take a fortitude save (DC equal to 10, plus the damage dealt) or be deafened for one round.
Craft (Mechanical) DC 19; Price 20,000 GP; weight 1 lb

Hardened Helm
While a normal helmet doesn't normally meaningfully contribute to your armour class, a hardened helm does, and in fact provides anything from a +1 to a +5 helmet bonus to armour class. A helmet bonus is ignored by the same kind of thing (such as a touch attack or caltrops) that would ignore an armour bonus, but it's not one and stacks with one.
Craft (Armoursmithing) DC 12 (+1), 15 (+2), 18 (+3), 21 (+4), 24 (+5); Price 2000 GP (+1), 8000 GP (+2), 18,000 (+3), 32,000 GP (+4) or 50,000 GP (+5); weight 2 lb

Lustrous Hat
This hat makes the wearer look exceptionally suave and sassy, to the effect of granting a +3 bonus on all charisma-based checks.
Craft (Clothesmaking) DC 14; Price 4,500 GP; weight 1/2 lb

Mask of Water Breathing
This mask does not actually allow you to breathe water, but it is attached to a tank which contains enough air for you to breathe for 3 hours despite only containing what would normally be about 10 minutes' worth of air if the machine didn't pressurise it. Unfortunately, it takes a minute of working the tank to get it to refill, which is hard work and can't reasonably be done while resting.
Craft (Mechanical) DC 17; Price 6,000 GP; weight - (mask) and 10 lb (tank)

Eye Slot

False Blindfold
This blindfold does not impair vision. However, it does protect against gaze attacks.
Craft (Clothesmaking) DC 8; Price 10 GP; Weight -

Goggles of Nightvision
Less effective than real goggles of the night, these glasses grant the wearer darkvision (60 feet) but no other vision. The wearer cannot see through invisible creatures, so although they cannot see the creatures themselves they appear as a black patch in the wearer's vision.

Normal darkvision is in black and white, but the goggles make the scene appear in green and white instead.
Craft (Glassworking) DC 17; Price 10,000 GP; weight -

Mirrored Glasses
A favourite of those dealing with meddling mesmerists, these glasses reflect gaze attacks which are fired upon the wearer back upon the user. They also work as normal mirrors when viewed from the outside, and may actually be real spectacles when viewed from the inside.
Craft (Glassworking) DC 10 (16 if functional spectacles); Price 20 GP (50 GP if functional spectacles); weight -

Neck Slot

Choker of Exploding Shrapnel
The choker is mildly uncomfortable to wear, but by contorting one's neck into the correct position, one can cause it to bombard those around the wielder with pieces of metal stuffed into holes in the neck, dealing 1d6 points of damage to each creature within 5 feet as a free action. Reloading the choker takes 1 minute, and can't really be done while worn.
Craft (Mechanical) DC 14; Price 1,500 GP; weight 1 lb (3 lb when loaded).

Periapt of Escape
This appears to be a perfectly normal necklace, but is made of adamantine wire and can be used to break through a steel bar in about a minute when taken off.
Craft (Jewellery) DC 16; Price 2,000 GP

Quickdraw Necklace
This necklace is designed for one specific light weapon on creation, and once created, it cannot be changed. When loaded with a weapon of the relevant type of the correct size, it allows that weapon to be drawn by the wearer as a free action. Trying to draw the weapon from another willing creature's possession requires a DC 15 sleight of hand check; to do so requires the same check increased by the creature's reflex save result (minimum DC 15 even if the result is negative).
Craft (Mechanical) DC 16; Price 6,000 GP, weight 1 lb.

Necklace of Hiding
A necklace of hiding has a tiny compartment inside. Finding it at all requires a DC 25 search check, and working out how to open it requires a DC 25 disable device check, so it is normally shown to a new buyer. Each necklace has a different opening mechanism. The necklace's secret compartment is big enough to hide something as big as a potion or poison bottle in.

The necklace has a few other interesting qualities. First, there is an array of 5 adamantine needles at the top of the necklace, with handles disguised as jewels at the top, which require a DC 25 search check to notice (Though if one is missing, leaving the pattern asymmetrical, the DC is only 15 to notice this, although it may not immediately be clear why this is the case. The needles can be used as daggers of their size. Also, wound tightly into the body of the necklace, there is a string of length 30 feet, which is thin, but made of adamantine wire and almost impervious to damage. If you let go of the string, it recoils back into the necklace almost instantly unless tied to something. Finally, the necklace itself is also made of adamantine and strong enough to use as a buckler, and two straps are hidden on the back which can be pulled down to turn it into one.

Craft (Mechanical) DC 23; Cost 25,000 GP; Weight 3 lbs (Plus weight of needles and contents of compartment)

Body Slot

Camouflage Shirt
A camouflage shirt is made for some specific kind of terrain, like forests or tundras. In that terrain, it provides a +10 bonus to hide checks; in a similar location (in colour, mainly, rather than actual similarity, such as urban camouflage and snow camouflage) it still provides a +5 bonus, otherwise it is ineffective.
Craft (Clothesmaking) DC 10; Cost 100 GP; Weight 1 lb.

Fireproof Vest
Not actually entirely fireproof, the vest provides resistance to fire 10. The wearer is not at risk of catching on fire by any means.
Craft (Clothesmaking) DC 15; Cost 13,000 GP; Weight 1 lb

Raiment of the Vampiric Flight
A creature wearing a Raiment of the Vampiric Flight can hide while running, and gains a +5 bonus on their hide check, so long as they throw the raiment off their body as they do so. When thrown in this manner, the Raiment appears to fly forwards at a rate of 60 feet per round for 1d3 rounds, then a rate of 40 feet forwards and 20 feet down until it lands. It is difficult to discern that the raiment is not actually a flying creature, and a DC 25 spot check is needed to do so.
Craft (Clothesmaking) DC 21; Cost 6,000 GP; Weight 2 lbs

Vestment of the Protector
This robe is made of metallic threads, providing defence while also allowing the wielder to remain unarmoured. It provides an armour bonus of +5 to the wearer but isn't actually treated as actual armour.
Craft (Clothesmaking) DC 16; Cost 25,000 GP; Weight 4 lbs

Robe or Armour Slot

Buoyant armour includes a component that helps the user float. While it's not enough to make the wearer actually float normally, it cancels the armour check penalty for the swim skill.
Craft (Armoursmithing) +2; Cost double; Weight +1 lb

Reflecting armour works exactly as normal armour of the same type, except that whenever a creature attacking the wearer rolls a natural 1 on the attack roll, their weapon bounces off and hits them; resolve the hit as normal against them. If using a critical miss variant system, the armour takes effect on the roll of a natural 2 instead, but only if the attack actually misses.

The armour can deflect melee and ranged attacks and even rays off its surface.
Craft (Armoursmithing) DC +5; Cost +10,000 GP; Weight +0 lbs.

Robe of Blades
This robe is a mass of protruding blades which make your movements deadly. When you move out of a space within 5 feet of a creature, that creature takes 1d6 points of slashing damage from the movements. If you run past that creature, they take 2d6 points of damage instead.

You can also attempt to whirl about as a standard action, in which case each creature within 5 feet takes 2d6 points of slashing damage.
Craft (Clothesmaking) DC 21; Cost 24,000 GP; Weight 4 lbs

Robe of Falling
A creature wearing this robe finds that it expands like a parachute, causing them to fall slowly enough to avoid damage.
Craft (Clothesmaking) DC 17; Cost 3,000 GP; Weight 3 lbs.

Belt Slot

Belt of Buoyancy
This belt is actually a thin tarpaulin-like object which is wrapped up to be small enough to wear as a belt. When unwrapped, it is a 10 foot by 10 foot sheet that can hold 200 pounds without sinking when placed on water, and can be used as a boat due to the slight upturn on its edges. Noticing the belt's true purpose requires a DC 25 spot check.
Craft (Clothesmaking) DC 18; Cost 4000 GP; Weight 1 lb

Belt of the Quicklash
A creature wearing this belt can unequip it and attack with it as a swift action. It deals 1d6 points of slashing damage when the attack is made and requires a free hand. When in the hand, it continues to function as a light slashing weapon that deals 1d6 points of damage (the damage assumes a medium creature).
Craft (Weaponsmithing) DC 14; Cost 2,000 GP; Weight 2 lbs

Cloak Slot

Cloak of the Elements
This simple cloak generally provides a shield against sandstorms, rainstorms and snowstorms of whatever kind, and provides a level of protection against heat or cold.
Craft (Clothesmaking) DC 21; Cost 12000 GP; Weight 1 lb

Cloak of Suffocating
This cloak's outside clings to most things that it touches, allowing a creature to use it to try to suffocate a creature as a swift action. If the attack hits, the creature hit with the cloak immediately needs to save against suffocation and usually blinds the target, though the cloak can be thrown off as a full-round action. It isn't effective against creatures who don't need to breathe, but might still blind them.
Craft (Clothesmaking) DC 14; Cost 1500 GP; Weight 2 lbs

Throwing Cloak
A creature wearing a throwing cloak can lob it as a swift action, which causes the cloak to fly up to 300 feet. Moreover, the cloak can carry up to 5 lbs of items inside it and still be thrown this far. If weaponised, it deals no damage, not even if the wielder has some other way of dealing damage such as sneak attack.
Craft (Clothesmaking) DC 17; Cost 500 GP; Weight 1 lb

Bracer or Bracelet Slot

Bracers of Crossbows
A creature with bracers of crossbows can fire one or both of the crossbows as a swift action. Each one is treated as a hand crossbow, except that it's a simple weapon.
Craft (Bowmaking) DC 20; Cost 2000 GP; Weight 2 lbs

Holding Bracers
A holding bracer allows you to carry a torch, or similar item, on your wrist instead of your hand, allowing you to attack while also carrying a torch on the same arm with no penalty.
Craft (Jewellery) DC 12; Cost 400 GP; Weight 1 lb.

Glove or Gauntlet Slot

Brass Knuckles of the Legendary Monk
This simple brass object consists of four fingerholes but no thumb-hole, and a piece of metal that fits into the user's palm. Atop the outside edges of the rings that serve as fingerholes is an array of studs which make being punched far more painful. A creature using Brass Knuckles of the Legendary Monk cannot wield weapons, but their unarmed strikes deal damage as though they were two size categories larger.
Craft (Jewellery) DC 25; Cost 60,000 GP; Weight 2 lbs

Gloves of Gripping
These gloves are made of an adhesive but durable substance which causes you to gain a +5 circumstance bonus to all checks related to holding onto something, including but not limiting checks to climb or to prevent being disarmed. They are ineffective when wet but water does not permanently affect them in any way.
Craft (Clothesmaking) DC 14; Cost 4,500 GP; Weight 1 lb.

Gloves of Protection
These gloves are used to prevent damage to the hands while working with dangerous materials, and render you immune to whatever negative effects you might normally take from touching, making an unarmed strike against, or making a weapon attack against an object or creature. For example, you can wield an unholy weapon as a good character with impunity.
Craft (Clothesmaking) DC 13; Cost 2,000 GP; Weight 3 lbs

Ring Slot

Bladed Ring
As a swift action, the wielder of the bladed ring can slash at a foe for 1 point of slashing damage with the bladed ring (wearing 2 is essentially pointless). Favoured by rogues, they can be poisoned and used to deliver sneak attacks, but they aren't weapons and you don't take a penalty for using one in your offhand. If you are devoid of any other weapons (or if for whatever reason you don't want to use them), attacks of opportunity can be made with the ring.
Craft (Jewellery) DC 16; Cost 6,000 GP; Weight 2 lbs.

Soluble Ring
This ring is, to all inspection, a normal ring. However, when it is taken off and slipped into a drink, it manifests its true nature as some kind of ingested poison.
Craft (Poisonmaking) DC +3; Cost +200 GP; Weight +0 lbs

Boots and Shoes

Boots of Trampling
A creature wearing boots of trampling who walks on a creature by any means - usually by overrunning them or because that creature is prone - deals their unarmed strike damage to that creature.
Craft (Clothesmaking) DC 12; Cost 600 GP; Weight 1 lb.

Shoes of Tracelessness
These shoes don't actually leave no tracks, but the tracks they do leave are much harder to follow. Add 10 to the survival DC to identify, follow, or do practically anything else with the tracks.
Craft (Clothesmaking) DC 13; Cost 1200 GP; Weight 2 lbs

Springshoes allow a creature to bounce a very large distance, making it practically impossible to walk normally but instead allowing impressive jumps. A creature with springshoes gets a +20 bonus to jump checks, but they cannot walk or run normally, instead having to jump wherever they move. A creature wearing springshoes can't withdraw or take a 5-foot step, and is always flat-footed in combat. However, fighting a rapidly bouncing opponent is genuinely impractical, but so is being one - the creature gets a +5 circumstance bonus to AC but a -5 penalty on attack rolls.

Springshoes can be used to give a +5 bonus to perform (Dance) checks.
Craft (Mechanical) DC 17; Cost 7000 GP; Weight 3 lbs.

Other items

Clockwork Construct
A clockwork construct follows a simple predetermined routine, such as charging at a target (hypothetical or actually existent) in front of it every round. This makes it largely useless in combat, but some are useful at specific tasks. A clockwork construct emulates a creature of some type except that it is a construct. To use it, you must wind it up for one minute per hour you intend to use it (or one round per six minutes you intend to use it). A standard action is about three seconds; a move action is about two; a swift action is about one. Therefore, even if you only wind the construct as a swift action, it will act for one minute, following its predetermined program from wherever it left off.

Cat or Dog: Craft (Mechanical) DC 13; Cost 5,000 GP
Human Warrior Skeleton: Craft (Mechanical) DC 14; Cost 6,000 GP
Mule: Craft (Mechanical) DC 18; Cost 10,000 GP
Heavy Warhorse: Craft (Mechanical) DC 27; Cost 24,000 GP

Horn of Winds
This horn needs no creature to play it; it can be heard as long as at least a moderate wind is blowing through the mouthpiece. It can still be played as normal, though.
Craft (Instruments) DC 12; Cost 200 GP; Weight 5lbs.

Rod of Destruction
One end of this rod boasts what looks to be a large claw. The other has a handle. When the Rod of Destruction is held to a surface and the handle is pulled, the claw deals 10d6 points of damage to the surface. This continues each round while the handle is pulled.

A rod of destruction is not really a conventional weapon, but it is inevitable that someone will want to use it as one: treat it as a club or as a shortspear depending on which end it is wielded from.
Craft (Mechanical) DC 18; Cost 16,000 GP; Weight 5 lbs

Rod of Sparks
When the rod is activated by turning the switch on its side repeatedly, it fires a barrage of sparks, causing a flammable creature or object within 5 feet to catch on fire.
Craft (Mechanical) DC 15; Cost 1200 GP; Weight 5 lbs