Here is one of the techniques I use to attain the rotting flesh look. This method involves using plastic wrap, a heat gun, wood stain, spray paint and craft paint. First wrap your cheap skulls or bones in a few layers of plastic food wrap. It doesn't matter what brand. Then take your heat gun and melt areas away until you get your desired look. Some hairdryers may be able to get hot enough to do this to. Then take your wood stain (I think i used an oak on the skull - just because that is what I had laying around.) and paints and start adding a little color. Color choices are completely up to you but i used red, flesh, dk brown, black, white, grey.