Accessories of the prepared trickster.
The once supreme cat burglar Tausmius owed no small degree of her success to her blending of skills in stealth with those of spell casting. Whatever the situation she was always ready for it. Those who knew her were as much in awe of her (many claimed magical) foresight into situations as they were of her audacity and skill in carrying out heists that all thought impossible.

What nobody knew what that Tausmius owed a great deal of her success to not foresight but to his acquiring a number of items that enhanced her already impressive flexibility.

Unfortunately for Tausmius she lacked true foresight, and after the theft of the tiara of Princess Flaris she lacked the wisdom to keep her mouth quiet about her success. Her body was found two days later, garrotted. The items following, missing from her body, have been rumoured to be helping various assassins in their daily tasks ever since.

Dagger of silence: This +1 dagger has a strange hollow on the back of the blade. It allows the wielder to invoke a silence (as the spell, save DC12) once per day. This can be centred on a person struck by the dagger (as a free action at the time of the dagger strike), or just used normally. The silence lasts for three minutes.
Faint illusion; CL 3rd; Craft Magic Arms and Armour, silence; Price 4462gp, Cost 2080gp +167xp

Ring of trickery: This magical ring contains within it the knowledge of a number of spells. While at first appearance similar in nature to a ring of spell storing this item is actually quite different. While the ring bestows knowledge of the spells is contained, the power to cast them is not. The wielder of the ring of trickery must channel spell of their own into the ring, which will then transform the power into another incantation. The spell being cast must be the same or higher level than the effect desired. Tausmius’ ring of trickery could transform spells into the following illusions: Ghost-sound (level0), Ventriloquism (level1), Misdirection (level 2), and Major Image (level 3). The spells a ring can transform are determined at the time of ring creation.
Faint illusion; CL 5th (or higher); Forge Ring; Ghost-sound, Ventriloquism, Misdirection, Major Image; Price 4225gp;
[NB this has been calculated as a competence bonus as +6.5 as it effectively gives 6.5 levels worth of spell knowledge.
There is no good way I know of to calculate this type of effect as they don’t exist at the moment – the closest alternative would probably metamagic rods - I'm welcoming suggestions on this.]

Cape of twisting: The cape of twisting is normally a whitish grey shade, but when placed next to an object, quickly takes on the shade and patterning of that object. Similar to the cloak of Elvenkind this gives its wearer a +5 competence bonus to any hide checks while wearing it. The major power of the cape however is that twice per day the wearer can twirl in a circle, transforming into a little whirlwind and then thin air. This is exactly the same as the use of the spell Gaseous Form, each use lasting for up to ten minutes.
Faint illusion, faint transformation; CL 5th; Craft wondrous item, gageous form, ten ranks in hide. Price 24100gp

Boots of Escape: These are soft, comfortable boots with a good grip. The toes are capped with a small spike (not useful in combat) that can help with climbing. As a free action they can once per day they allow the user a burst of speed for one minute that allows them to escape most immediate trouble. This effect is exactly the same as the spell Expeditious Retreat. Once per day they also allow the user to Spider Climb for half an hour.
Faint transformation; CL 3st; Craft wondrous item, spider climb, expeditious retreat. Price 4680gp

Ring of Retaining: Perhaps the most prized possession of the arcane trickster, her Ring of Retaining allowed Tausmius to keep a variety of spells in mind, reusing those most appropriate to the occasion. Twice per day, the round after casting an arcane spell of third level or less, the character may concentrate on the ring and have the spell returned to her mind.
Moderate Transformation; CL 7th; Forge Ring, Rarys mnemonic enhancer; Price 20160gp