I think it doesn't look great to have no earrings in with pierced ears. I'd a necklace. ..studs (unless it's a party look)
This necklace. .. Small earrings (hoops, dangling) also okay as it's not huge
The 'rule' (I used to work in the jewellery trade) is to wear max 2 of the 3 staples... so necklace, earrings, ring. Small studs, wedding ring does not count... engagement ring... depends on size.
Wearing 1 statement piece only okay (eg small studs, blinding ring/necklace ), all 3 is a bit Xmas tree (for all but most gala occasions and even then 2 of 3 is more classy)
But... rules are meant to be broken - yesterday I had in diamond studs, statement necklace in black/gold, a bold ish gold ring, gold watch and a subtle gold and diamond bracelet. .. but with all black simple outfit. .. jeans and t. Fewer accessories if outfit has more going on