Well it is all depending on the variety of setups they can use against various of opponents.
Assuming you are refering to a bvc/bva the normal setup would be to reach 63fcr bp and this is done with something like trang gloves (20), arach (20), circlet (20) + 1x fcr ring & 1x wisp projector. That would be the standard fpk setup.
This is also assuming you are running a Cham in your circlet, otherwise the second ring would have to be a raven for cbf source.
Rings:
Wisp
Fcr ring
Raven
Angelics (extra AR, against i.e melee opponents like smiters)
Amulets:
Fcr amu to hit bps with other setups
Highlords amu (main)
Angelic amu
I would say those are the most common uses of jewellery.
D2:R