Looking For.... Bottle Cap Tutorial

Do any of my a-maze-ing crafty friends out there have, or know of, a tutorial on how to make bottlecap images?

The basic idea is sound- use clip art, put 12 to a sheet, get em printed on photo paper, use 1" round paper punch, punch em out, glue em, coat em.

But, since I've never seen an -actual- sheet, I don't know what size I should design in. Or, what the best top coat is for once the images are on the bottle cap. Would Mod Podge be enough, or should I use Epoxy?

Point me to your directions, I'm desperate!