Don’t just lurk on Twitter. Converse. You’ll learn more by playing than you will by lurking.
Be human. Have a story to tell, instead of a message to push.
Share your experiences.
Plug – if you must – but flag it as a plug.
Rickroll people sometimes. Everyone’s trying to do it ;-)
(If you don’t know what Rickrolling is, figuring that out is a good start)