From my personal experience having just taken it up as a craft a few months ago, the most cost effective option is to buy dishwasher safe 2 part epoxy, dishwasher safe clear coat, and gold mica powder separately online. That's what most sets are made of, but you get a much greater quantity if you get them individually.

Personally I went with food and dishwasher safe options because I plan on doing it to fill the chips in a 70's easter pastel dinner collection that my partner and I absolutely love. The juxtaposition of honorable Japanese artist craft on ketchy Americana dinnerware just delights us. Bonus points is that mica powder comes in a lot of colors so you don't have to only use gold! Personally I feel copper on black glazed ceramic would be gorgeous but you can also get glow in the darks and thermoreactive.