Add soft shading to all of the flesh with a 1:1 mix of Screaming Skull and Baneblade Brown . This may take a couple of passes. I like to thin with Lahmian Medium and be particularly generous on the lower half of the leg, which gets an all over glaze, pulling the brush downwards.
Shade more selectively with pure Baneblade Brown . Again, be more generous on the lower half of the leg.
In particularly deep recesses, run some Dryad Bark in, for extra definition. This is also a good colour for darkening the eye sockets and where the "flesh" meets other materials too.
As an optional bonus stage, consider a glaze of Seraphim Sepia on the lower half of the leg and other heavily shaded areas. I found this brought a little more warmth and variation to the skin, making it look more alive.
Edge highlight with 1:1 Screaming Skull and White .