To produce lean and marketable prose, ask for a 1,000 word piece. Comment on it and then ask them to make it better and hand it in again. Then take the finished product and ask them to cut it by 200 words. (This works particularly well on the boy genius who is convinced that phd. means "piled higher and deeper.")
I wish DS12's teacher last year would have followed this guideline. She required a 7 page paper on a famous person, and then had the whole class cut it down to 3 pages. very emotionally tough on DS
