Bryan Caplan gives some guidelines on writing non-fiction

I try to write the kind of books I'd like to read, and I try to read the kind of books I'd like to write. This isn't as narcissistic as it sounds.  I'd like to write like Tolstoy or Alan Moore or Steve Landsburg, but I have to settle for being me.  

5. When in doubt, write like Hemingway.  If you can delete a word without changing the meaning of a sentence, do so.

Read it all here.