I got this from the extras on the Jackie Brown Redux DVD: Elmore Leonard's rules for writing.

1. Never open a book with weather.
2. Avoid prologues.
3. Never use a verb other than 'said' to carry dialog.
4. Never use an adverb to modify the verb 'said.'
5. Keep your exclamation points under control.
6. Never use the words 'suddenly' or 'all hell broke loose.'
7. Use regional dialect sparingly.
8. Avoid detailed descriptions of characters.
9. Don't go into great detail describing places and things.
10. Try to leave out the part that readers tend to skip.
11. If it sounds like writing, rewrite it.
12. For all these rules there are always exceptions.

Stephen King says pretty much the same thing about adverbs.