Here's a 110mm white metal kit from 'Andrea Miniatures' I painted up using a mix of enamel & acrylics
What you need to know is there should be some
blue in your flesh tones. Humbrol 61 and Revell 35 are no good straight from the tin but need the addition of some red (a darkish one) and blue to get a colour that's less jaundiced-looking... then some white to lighten it . More white for a smaller 54mm figure because you want to be thinking about 'scale colour' too
I first paint on a base of matt flesh colour, then dampen the dried surface with water to allow a faint dab of a rose red acrylic colour to be softly tickled into the cheek areas using a small brush. The damp surface means you can soften this so it just slightly colours the cheeks up. You can see this in my photo
Then I'll use the same method to work a thin grey-brown colour around where facial stubble would be on a soldier who didn't always get time to shave. Also do this on any bare forearms, although a 'scumbling' of grey brown using a 'dry brush technique' (stroking
across) makes for the most realistic arm-hair
A more general wash of very thin red-brownish acrylic can be useful to bring out any good relief detail such as around the eyes and ears, although this shouldn't be overdone
For the lips I use the flesh colour I've already settled on but add a little more blue and red to give a 'plum' colour - but not too dark
Eyebrows and pupils I then pick out with a small brush using a thin acrylic brown. And I
NEVER ever paint the whites of the eyes; when you're standing a distance from someone you just don't really see these. So many great figures get ruined by 'zombie eyes'. Leave them flesh colour and just stroke in a tiny curved line to describe the upper eyelash line, then a short stroke downwards from this for the pupil... that's all I do