While I was at the Kid's Fudge Expo, I had my 10 year old daughter take some photos while I was doing a glitter tattoo. Sorry for the blurriness :). It gives you the general idea how it is done. I get my supplies from Glimmer Body Art.
Step 1: Apply the sticky stencil to clean skin.
Step 2: Apply the cosmetic glue inside the stencil
Step 3: Dab the first color of glitter onto the glue
Step 4: Apply cosmetic glue and the second color of glitter
Step 5: Gently remove the stencil