One of the fun things about working with enamel is that most pieces are double-sided. You need to apply glass to both sides of the metal -- we call this a "counter" -- so the enamel is even. If one side is thicker than the other, the metal can bend and the enamel can break off. So if you have three coats on side, you need three on the other. The only exception is if you're doing a technique like champleve, and are working with a very thick piece of metal.
I usually just apply a plain color as my counter, especially if I'm making something where only one side is ever seen. Lately, though, I've been working on the other side -- the "B side," if you will -- and turning my jewelry into two-in-one pieces. Here are the reversible heart necklaces that I designed:
I tried to go with extremely different color combinations so the pendants can be worn with a diverse range of outfits. I had a lot of fun making these and coming up with unique combos. Out of the four hearts, though, I think I like the pink, red, white and black the best. One of my classmates said that the red line looks like an aorta. I don't know if I want this kind of heart to look like the human organ...
So far, I've made double-sided cats, hearts, stars and abstract figures. I think it would be interesting to paint a cartoon-type character where one side is the person's front and the other, the back. I'll have to play around and see what I come up with. The other good thing about enamel is that if I screw up, I can always paint right over my mistake!