I'm working with gouache and start with a light wash over the figure. The wash puts a layer between you and the pencil lines so that they are less likely to rub off. Also, It benefits seeing the edges of the figure more clearly. I don't worry about the wash being uneven and having little blooms here and there since I have many more layers to go. Also, gouache lifts off the paper with water much more easily that watercolor, so I don't have to worry about areas being too dark in the areas of the figure receiving the most light.
With both the hair and the skin I work transparently. There are just a few highlights where I use opaque white paint.
I had the shirt "finished", but a wise classmate of mine pointed out the monotony and formlessness of the folds. I took new reference photos and started over. The shirt is the only place that I worked opaquely, which started out as a transparent painting might, but I used more paint and less water as I proceed with each layer. Once I got to a thick level of opaqueness, it was really tricky to add just the right amount of water that allowed me to blend in the new layer. Too much water and you remove all of the hard work you've done in previous layers, which I encountered frequently. I don't know how Harry Anderson did it.
Almost there! I just need to clean up the scan and add text.