Need help homebrewing a magical item!

[Bakenal]

So let me start by saying I will pretty unabashedly homebrewing sweet magic items. None of my party are huge min/maxers so I'm not too afraid of accidentally giving them something game breaking. That being said I decided it would be a cool idea to give my party the choice of an entire treasure room full of items, coins, and jewels. Some magical and some mundane. Obviously after drawing out this awesome layout (just learned I can't post links yet) I kinda nudged the party towards certain items crafted for them. But it backfired a bit as 2 of my group just decided to grab items they thought looked cool rather than geared towards their class. (monk took the wraps that cause bleeding, sorceress took the dissappearing cloak, cleric took the statue that turns into a mount). The two items that were out of sync was the bard who took a set of bells in a bandolier (if anyone has read the abhorsen series that's where I got the idea). And a fighter who took a bejeweled corinthian helmet. These two items I hadn't really thought out as far as their function. The helmet i am thinking could be used to inspire fear, courage, or compel a challenge on some foe. The bells I am not certain how I should proceed. Since you guys have been pretty awesome at helping me with ideas in the past I wanted to see if you guys had any ideas.

Thanks!

[Baptor]

Bells in a Bandolier (maybe works like a weapon of warning?)

Helm with Horns (lots you can do here, magic resistance maybe?)

[FlourescentKing]

"HERE COME THE BELLS"
I'm sorry, whenever I imagine spherical objects on a bandolier, all I can think of are grenades. Sonic grenades - perhaps they explode, dealing thunder damage? Another idea is ringing them to dispel enchantments/charm-like abilities. Bells of Warning seems a bit obvious, but it works....

Edit: Another interesting idea would be to let the bard store spells in the bells - it's like potions, but for music! I have no idea how powerful this is, so proceed with caution....

Also, the different gems in the help could change the damage type...I dunno....

[Bakenal]

I like the idea of them being imbued with some sort of charming or beguiling abilities rather than just warning, which really would not put them on the same level as the other items.

[Bakenal]

A picture of the treasures trove to help visualize btw (https://imgur.com/gallery/ENG5w)

[Zman]

How about each bell can cast a spell once per day. One casts Alarm. One casts Shatter. One casts Chromatic Orb(Thunder), and one casts Thunderwave.

The Helm could do a ton of stuff, or just be a Luck Helm. Once per day it can turn a roll of a 1 into a success on Attack Rolls, Skill a Checks, or a Save.

[RickAllison]

"HERE COME THE BELLS"
I'm sorry, whenever I imagine spherical objects on a bandolier, all I can think of are grenades. Sonic grenades - perhaps they explode, dealing thunder damage? Another idea is ringing them to dispel enchantments/charm-like abilities. Bells of Warning seems a bit obvious, but it works....

Actually, this is a really fun idea. You might look up the Equalizer grenades used by TAsk Force:VALKYRIE in nWoD. They function by using sonic and light emissions to disable the shape changing of werewolves and other supernaturals. That seems like a really cool ability for a bard, and you could have it replenish maybe 1 per dawn. That way it is a limited resource, but a potent one.

[Foxhound438]

a) attach a 1st or 2nd level spell once per day effect. Helm could be color spray since it's bejeweled, bells could be silence because... well, unintuition.

b) helm in specific could give the wearer a horn attack, ie. "as an action you can make a melee weapon attack with the helm's horns. it deals 1d10+str, or 4d10+str if you moved at least 20 feet in a line towards the target immidiately before the attack. On a hit, the creature makes a dc (number) strength save or is knocked back 15 feet and lands prone."

c) charming ghosts and having improved influence might be good for the bells.

[Renvir]

If you go with any spell effects make sure the effect isn't too much more powerful than the character's current level. A level 5 bard with access to bells that cast level 7 spells (an effect that normally can't be used until the character hits level 13) can be devastating. Looking through the spell book for spells at the players current level is a great start as well as a trip the magic item section of the DMG.

I learned this the hard way and had to go back and change a few items after they made things too easy for the players.

[Reaper34]

What did they turn down and what did it do? could just need to reskin it.

or each bell works as a single use/day wand each casting a diferent spell.

too many ideas to list for the helm.