All the following colors are Vallejo model color (except for the dark fleshtone which is from their game line):
After priming with Floquil from a spray can, either gray or white, I lay down a layer of beige red lightly thinned for caucasian skin. For the creases, I add varying amounts of dark fleshtone. For the highlights, I'll add pale flesh, sunny skin tone, basic flesh, or dark flesh, ending with straight pale flesh. The higher a deeper the values, the more thinning. Thinning is done with distilled water, about $2 a gallon from the local CVS. These paints do not create a wash, per se, and you should try to lay in your shadows and highlights right where you want them, building up very thin layers. The paint will dry adequately for another coat in a couple minutes at most and will not lift up like Tamiya.
I'm doing a female figure right now and I'm using basic skin tone since this is lighter and pinker, more befitting the female form.
For darker or more tanned skin, I'll start with a base color of beige red and dark fleshtone in varying ratios to meet my needs. To help blend in the layers, I'll periodically lay on a very thin layer of the most recent clor I've used.
You can see the results here and here. While these are large scale faces, they process is the same.