OK, I'll bite...

I usually basecoat with GW Bubonic Brown. Then a wash of dilluted brown ink. Then back with the Bubonic Brown, and this gets mixed up with white (usually Vallejo Game Colour) to the highest tone I like. Most faces in 28 mm will take me through 5 or 6 layers, with some light wet blending here and there (forehead and cheeks). Highest highlight is usually some white on the cheekbones, nose and brows. The overal look can of course be varied to match the skin tone of your liking.
I mix in some (very, very tiny amount of) red into the mix for the colour of the lips and sometimes a bit on the cheeks as well (ruddy dwarf faces for example). Some purple can be used as well, for righs under the eyes or a general sickly look.
Some very light grey can be used for very old looking figures too btw...
Hope that helps.
