Re-Learning Colored Pencil

I'm starting a new colored pencil portrait, and remembering a few things that I had forgotten - like reserving white areas and color mixing - very different from oil! I'm working on sanded paper so I can apply lights over darks, but the resulting color is always a mix of the colors used, so it involves a bit of planning. Luckily, I work in layers, so I have many opportunities to adjust value and color. Here you can see the underdrawing done in dark umber, and the beginnings of some layers. The earlobe on the left and the scarf are pretty much done, though I may alter them later after working on other sections.