Here's another sketch from one of the weekly drawing sessions I've attended over the years. Most of my sketches from these sessions are done in charcoal pencil so I can focus on values. One main focus I have while drawing from life is learning the visual anatomy of the head and how that varies from person to person. Every once in a while, though, I like to break out the pastels or oil paints for a color study. Color certainly needs to be studied and practiced too, but it's easy to get caught up in the fun of color and neglect more important matters of drawing. For me, regularly doing monochromatic drawings helps the color studies.
For more about drawing sessions, go to "Labels" on the side bar and click on "sketching" or "drawing."