When it comes to jewelry in headshots, less is definitely more. The focus of your headshot should be on you and your expression, and jewelry tends to be more of a distraction than an enhancement. Unless certain jewelry is part of your brand or signature look, then it’s best to keep things minimal. Headshot photographer Garry Barrigan suggests that women wear no necklaces or chokers at all, and, if they must wear earrings, then opt for discreet studs.
If you DO plan to wear jewelry, I often like to shoot some shots with and without, so you can see the effect yourself. Nine times out of ten you will agree that the shots with no jewelry (or minimal jewelry) are far better.