This is a study in portraits using charcoal. my technique is once a laid the initial tone lightly I use a dry paint brush to shade it and then add darker layers then again use the brush to blend in the tones. one that is done I basically lightly outline the drawing then use a kneaded eraser to guide the drawing. In order for the highlights not to be to sharp I would go over the edges with the paint brush to soften them.

Olu