If wearing a necklace too I wear studs like spykid's in brown or orange (v cheap, BHS), or white gold diamond-esque ones (present from DH, prob Ernest Jones)
If no necklace (usu w high-necked tops) I have an assortment of 1" dangly bead ones in wood / bronze / gold / tigers eye /amber etc - all fairly old and mostly from Accesorize, craft fairs etc.