Hint #6: don’t be a jerk. I see some new users come to SO with a question with a complete sense of entitlement. They’ll ask a unclear question and then berate you if you don’t give an answer they don’t like. These people fortunately don’t last long since pretty soon no one will answer their questions. Then there are those experienced users who berate new users and insult them unnecessarily rather than coach them to success.

IMO StackOverflow could change some things to improve the collaborative atmosphere there:

1. Don’t allow downvotes without a comment (like several here have suggested)
2. Don’t allow a new user (reputation < 500) to post a question unless it includes a code block. This is the most common reason for early down-voting. It can be trapped in the editor fairly easily.
3. Perhaps provide a template for questions for new users so that they can see what elements make up a good question. Including the basic markup would also show new users how various elements can be formatted.