Mixing color: I spend quite a bit of time mixing up all my fleshtones and the neutrals for painting skin. Every element in the painting reflects its color on the skin of your subject.
Glazing, Blending and half tones: Transitions between areas of shadow and light are very important. I try to not make mine too smooth, so to avoid an "airbrushed" look. I enjoy seeing thick areas of painted piled up to define space, and luminous tones that "emerge" from the background. Glazing really gives the water a 3 dimensional glass-like appearance. You have to wait for each layer to try, but it's worth it.
She's not done, but she's close! I have to wait for her to cure up so I can glaze a bunch more, put a fish shadow on her skin, and to spend a bit more time on the water and kelp. Final photo coming in a couple weeks!