Classic elegant piercings obey a simple test: would this setup have looked appropriate at a dinner twenty years ago, and will it still at one twenty years from now? Placements pass that test when they follow the ear's natural anatomy — centered lobes, a helix that sits exactly on the rim's curve — and jewelry passes when it borrows from fine jewelry rather than fashion jewelry.
That is why the vocabulary is so stable: a round pearl, a bezel or prong-set diamond (or good cubic zirconia), a plain polished gold hoop. These shapes predate piercing trends entirely; they come from earrings your grandmother could have owned, which is precisely why they cannot go out of date.
Restraint is the other half. Elegance is partly negative space — one or two points of light on each ear, positioned precisely, with nothing competing. The moment counting is required, classic has ended and curation has begun.