I was inspired by the toy Barbie Geetar from the sixties. I followed the color scheme which was mostly red with a lot of thick black outlines. I painted a party version of myself and sprayed it with clear lacquer. I glued gems on the volume and tone knobs.
Since the pick ups control the tone painting the body did not affect the sound, I wouldn't do this to an acoustic guitar unless it was going to be wall art.
DO not try this unless the guitar you are using is one you dont care much about. Dont do this to your main guitar, or one that has alot of value. Save that for the pros. This will explain some basics to customizing the body of your guitar, by yourself. You need to be able to paint, in whatever way you want to do it. Some use spraypaint, and some use brushes. I think the best approach is the AirBrush that they use to paint tshirts with.