When girls leave jewellery in your room after a night out, or you end up claiming it after lots of kino, I guess she wants it back, what's the best way to deal with this?

I think I've noticed guys using a girl's jewellery as a way of getting them to come back, how does this work?

I also naturally use jewellery a girl is wearing as a way of initiating kino sometimes especially to start holding hands. Now I have someone's watch.

Do any of you guys ever use this technique to initiate kino? also what do you do when you end up with a piece of someone else's valuable jewellery? Obviously this isn't for random encounters but more girls you've met before with their number or facebook atleast