Diana Carey was our model today. In my demonstration I showed you a "subtractive drawing" technique. I started by covering my drawing paper with an even coat of charcoal. With a charcoal still you will have to find the convex edge so you don't mark up you paper with a bunch of parallel lines. I did there or four coats of charcoal, smoothing out any texture with a shammy.
Next I used a pencil shaped eraser to rough in my usual gesture and stick figure. I drew in contour lines with a charcoal pencil and used my various erasers to erase out highlights. In the early stages of the drawing I usually will use the shammy to almost completely smear out my whole drawing. This helps me keep from getting detailed too quickly, helps me see more general issues with proportion and gesture. Wiping out a drawing also has the added benefit of creating a richer variety and layering of values.
After wiping out the drawing I would go back to erasing highlights and using more charcoal for shadows. This same technique can be used with soft graphite if you don't want to use charcoal. This technique is a really great way to get more three three-dimension in your drawings because you will tend to get a wider range of values.
Remember your highlights will not feel like highlights unless everything else (including negative space) in your drawing is a darker value.
See the video below to see how charcoal powder is used. I don't want anyone using charcoal powder in the classroom, but some of you might enjoy playing with it. You can buy it at Blick but be careful using it - you don't want to be inhaling a lot of it.