This article is from the Miniatures Painting FAQ, by Brenda Klein firstname.lastname@example.org with numerous contributions by others.
Start with the eyes. Then do the face in whatever shade you
choose. Now add a touch of white to the flesh tone to get a
slightly lighter shade and go back over the nose and cheekbones.
A light orange makes defined but natural-looking lips. Remember,
red lips are a product of makeup, not nature.
Some painters prefer to put the eyes on last, but others say it's
too hard to keep from making the effect pop-eyed when done last.
Try whatever method you prefer.
Moustaches are best if dry-brushed, paint beards a slightly redder
or darker shade than the hair and dry brush with the same colour
you use on the hair. There's nothing wrong with a 5-o'clock
shadow on an appropriate figure, either. Dry-brush it on in a
shade slightly darker than the hair. Once you get comfortable
with faces, experiment with scars or tattoos. You might amaze