Julie modeled for my recent Prescott workshop and although I didn't get to paint her, I did have benefit of studying her face from many angles, over many hours' time. Below is my morning study.
Step 1: Size and place the head. Drawn with Raw Umber, thinned with a bit of Gamblin's Solvent-free Gel Medium.
Step 2: Separate light and shadow; commit to the background.
Step 3: Block in general skin tones, one for light and one for shadow.
Step 4: Add some detail to the features.
Step 5: Develop the forms of the face and hair, and continue with detail.
Step 6: Refine transitions, correct drawing mistakes, run out of time:)
Julie, oil, 20 x 16