For this exercise we started out by putting down a layer of cross-hatching over the entire sheet of paper with a medium weight lead. Then instead of just drawing the figure, we drew the LIGHT by either darkening areas, or using the eraser to "pull-out" the white areas. I really liked this exercise and felt like a did a good job with my second one (where the light was positioned below)
2 @ 18" x 24" - Pencil - 2005