first work with watercolor portraits

I've recently started trying to paint figures and faces with watercolor, which I find to be tricky, but really interesting.  I'm finding that getting each wash to be the right value, neither too light nor too dark, is probably the hardest part (other than accurate skin tones, which I'm sure just gets better with practice...some of my paintings ended up looking quite sunburned or jaundiced).  I really like how these exercises are really making me pay attention to hard and soft edges, and to how the different planes of the face or the body turn away from the light.