Advice for creating makeup?

Upirium

Well, not so much makeup as body paint...
i want to create something like the pics below

I'm sure I can find better pics of his makeup/ body paint for future references when I try to do it, but I have these right now...
I know HOW to do it. Like what programs to use, and that I have to edit the skin map but I've never actually drawn on anything before.
When I edit my skins I usually take PNGS or something and paste them on there.
The person in question that I am doing, I have already added the tattoos because he was conveniently in a magazine where he showed off all of them, high res and large. They're not even that great but they're 'good enough'. Except for his back. There is just no way. It goes down past his waistband and there are no pictures of that.
I will attach pics of that too
Some of them are covered but...
Anyway, yeah.