Skin Step 1
I gave the skin a basecoat of Dark Flesh. Since I use thinned paint, I built it up with several coats to get a good, solid basecolour.
Skin Step 2
Using a mix of 50/50 Dark Flesh + (GW) Tanned Flesh, I painted over the basecoat, only leaving it showing through in the deepest recesses.
Skin Step 3
Using Tanned Flesh, I built up the highlights on the more pronounced areas (upper surfaces of the arms, body and face).
Skin Step 4
The next highlight was built up using a mix of 50/50 Tanned Flesh + (GW) Dwarf Flesh.
Skin Step 5
The final highlight uses Dwarf Flesh, concentrating on the very highest points (knuckles, nose, cheekbones, etc.).