The boys wanted Minecraft pinewood derby cars for Cub Scouts which worked out perfectly. I put together a rough template or "skin" for the characters they wanted from Minecraft (Creeper and Steve), we printed them out on regular sheets of white paper. Cut them to size, folded them to fit the blocks of wood that came with the derby kits and then glued on the wood. We finished the "skins" with a coat of Mod Podge craft glue.
Below are samples of the templates we used. They are far from perfect, but they worked for us!