Anything cursed ~
Say... a cursed calcite earring, which turned the wearer into a cute little kobold?
A cursed steel collar that brands obedience and certain commands fit for a slave into the one wearing it.
A toering, which robs and seals into it the power of another, who was made to give their essence to craft the accessoire!

Obviously I am a big fan of paw/foot accessories but also love anything else. Be it a necklace, be it an earring. The thing is... if it's a cursed item and does something to make the situation more arousing by either enforcing involuntary behavior or forcing the one wearing it to be more open about what's going on, or less powerful than they should be ~

I mean... imagine I put a steel collar on your which forces you to follow my every command and bracers on your wrists and ankles which force you into specific positions at my leisure!

Or I place a ring on your finger, which turns you into a golden statue of yourself!

God there's so many good ideas here!!