I was at the beach last week and there were several people there who had used their body as a canvas and the had large full body tatoos. On a couple there was so much going on that the overall design was lost among all the colors and pictures that had been applies to the skin. Personally, I feel that if you are going to use your body as a canvas, before doing anything you need to understand the principles of design, composition, and color so what is applied to the skin byt the tattoo artist is something that is a true work of art.
Here are some sites that better explain this then I can.
I love tattoos. I personally have one myself and plan on getting more. The only issue for me is when women who are very attractive go and ruin their bodies with large and bold tattoos. There is a certain point when the tattoo just becomes awful looking.