im missing a lot of the layers to this but heres the basic gist of it

1. i do my sketch, clean it up
2. then i add the basic values under it, keeping in mind like.. the skin is lighter than the shirt, and the shirt is lighter than the hair
3. then a multiply layer and i brush in the core shadows, cast shadows, etc
4. overlay layer with the lighting
4 and a half. then i do another opaque layer (not translucent like the multiply shadow layer) to "tighten" up the values, you know smooth things out
5. color or overlay layer .. heres where i mess up a lot :/ i usually throw down the base colors, then another layer for the shadows but on this particular study i accidently the shadows on the coloring layer also
5 and a half. another opaque layer to tighten things up
6. finished product, usually ill sharpen it or do colo rbalance until im happy with it


this is a technique im still trying to learn, its wonderful for value studies up until the coloring layer part which is where im usually S.O.L :X