1. When you see a tweet in your timeline that contains "breaking news," just retweet it. Don't re-type the news making it seem like you have some insight into the situation. Every story is "broken" this way by about a thousand fans.
2. Don't be the guy who puts @athletes usernames in every tweet. Once in a while, when it's relevant, is fine. But calling out for athletes in hopes that they retweet you is just lame.
3. When your team goes down ten in the first half, don't tweet "game over." This is basketball. It's not over.
4. Don't constantly complain about the refs, unless your username is something like @ACCRefsSuck, in which case go nuts.
5. Unless you really understand X's and O's, avoid tweeting about 3-point defense. Odds are you're wrong.
6. When a blogger/fan is tweeting about their team during a game, don't send them completely unrelated questions. In the middle of FSU vs Duke I could really give a crap about discussing coach Hamilton's salary or why FSU doesn't have better facilities.
7. Don't post pictures of your junk.
8. Don't listen to other advice about tweeting and avoid tweeting while drunk. Sure, you'll lose some followers, but it's great fun for the rest of us.
9. No one likes the angry fan in real life, and this is even more true on twitter. Don't be the angry fan.
10. Don't be this guy: