Now you should correct the shadows on the skin (fake SubSurface Scattering, SSS). The best tools for such operations are "Highlighter Brush II" and "Shading Enhancer". Use default alpha, with Focal Shift set to . Save your document and experiment.
Done? OK. Draw details, if you have forgotten about some parts (eg. the top of head or ears) and we can continue. Select "Simple Brush"/"Freehand" (lowest spacing), draw size ~. RGB Intensity . Alpha should be set to "Brush 32", Focal Shift to .
With dark brown color, make strong shadows on brows and lighter above ears. Change alpha to "Brush 31", RGB Int. to , Draw Size to -. tint to reddish gray.
Paint the "darker" fibers, then highlight hair and brows with light gray. If some parts are too bright, touch them up with shade from dark part of head ("Picker", then drag field near "Once Col" to the 3D View). It's all about drawing and correcting :) You can also load a texture, and use with with "Freehand" or "Drag Rect".
Finished! :D We've lowered red saturation a bit, and used Unsharp Mask filter.