My project advisor once gave me a piece of advice that changed everything I've written since for the better. After apologizing for the forthcoming crudeness, she passed on this gem: You're writing "Mary was fucked by John." You /should/ be writing "John fucked Mary." I can say what I need to say in half the words now.
If you want a whole lot more of those, I suggest Strunk & White: http://www.bartleby.com/141/