Some rules of thumb: Smooth plastics and painted surfaces have highlights that are small, well defined and the same color as the light around them. Textured plastic and paint is the same but with larger highlights. Smooth metal has small highlights that share the same color as the metal. Textured metal is the same but with larger highlights. Skin has highlights that are so diffused as to be nonexistent. Either set your highlight color to black, or set it to the color of the skin and then diffuse it with a hi-rez bump map. -SMT

I'd rather stay in my lane than lay in my stain!