I did this Avatar Birthday Cake for my niece’s 15th birthday. I looked all over the internet for pictures of the Avatar movie and found one that I printed out, resized, and then printed again. Then I cut it out and set it on the buttercream-iced cake. (The cake was a 1/2 sheet made from 2 store bought cake mixes.)
Then I traced around the paper with a toothpick. One more trick: Since the Avatar face has to be perfectly proportionate in order to look right, I cut around the facial features and cut them out. Then I knew exactly where they should be and what size. Then I filled in the cake with stars.