Finishing the Skin

Once my skin colour velatura is painted on the lighter areas, I start putting in red touches with vermillion red on the nose, cheeks, eyelids, lips, etc, and then I take pure white and paint it into the highlights, as seen in the first photo. Then I mix burnt umber and black and retouch the darkest lines in the mouth, eyelashes, nostrils, etc, with a very fine brush (you can see my hand slipped on the eyebrow in the second photo). I also drag white through the irises of the eyes for grey or blue eyes, and finally, big dabs of white for the reflections in the eyes.