Just the facts, ma'am...

Grace (25x15)

When sketching from the live model in one session, you just go for the facts; light & shadow, edges, value & colour....but no details. Details will bog you down with unnecessary information and cause you to lose spontaneity and kill the overall freshness of the picture. Instead of trying to record everything you see in the time allotted, edit as you go, deciding what's essential and what is extraneous -- it's surprising how little information is actually needed to capture the spirit of a subject. A few accent strokes will will do for the illusion of detail and help hold the shapes together... the tricky part is to know when to walk away and quit messing with it (something I have yet to learn my lesson on...)