Jump Into Jewelry with Aki ::: Skull Cameos
What you need:
You can also make a smaller one for a ring - all you need to do is resize the template before doing the DIY. Of course, attach it to a ring base. On the photo above, I filed down the skull a bit more to fit my kind-of-tiny-cameo. I mod-podged the background with some antique-looking paper (instead of painting it) before setting the skull.