for hair, try alternating highlight strips of browns, both light and dark sporadically throughout the sculpt. use a little fading at the roots along the hairline. go from very light (almost flesh tone) at the roots/hair part, gradually getting darker the further down the length of the hair you go. then apply random highlights to the dark areas and throughout the whole hair do. make sure you matte varnish/dull coat the face. For the hair, use matte, satin, or gloss varnish depending on the hair style.
wet look: shinier varnish
dry look: matte/dull coat
also, use gloss varnish for the eyes
eye tip: reflections on pupils, or the little white dots you see on the pupil and iris should always be on the insides of the eyes close to the nose.
those white dots you see people do are light reflections. when a light is placed in the center of someone's face, those reflections tell the doctors whether or not you have crossed eyes, or vision problems.
its a little known diagnostic short cut to shine a light in the eyes and look at the highlight placement to see if they match each other, and both reflect to the inside of each eye.
whew, that was long winded. apologies