Realistic Skin?

Hey im working on airbrushing my first picture, and im doing it over a Black and white photo. And i was wondering, if anyone could help me with making the skin look more realistic? Thanks.

ummm...choose whichever colours you like. I suggest opening a photo(colour) and use the colour picker on the darker skin tone, switch to foreground and pick the lighter skin tone, and work from those. lighter for high parts of the face, darker for lower parts, you could re-style the person's face if you wanted :|