- Don't spam with auto DM's (direct messages)! This is one of the fastest ways to get yourself unfollowed.
- Don't just post links to your "stuff". If you're only going to take about yourself, soon you'll only BE talking to yourself!
- Retweet interesting and helpful posts from other people.
- Interact with other tweeters - reply to their messages, ask them questions, congratulate them on sales, etc.
- Aim to tweet at least every few hours (but NOT every few minutes - don't overwhelm the system with a million tweets per minute!).
- Keep your tweets interesting. Vary from links, to questions, to observations, to "regular" stuff. Share all your fav finds on the web and try to be as helpful as possible. But try to keep links to a minimum so you don't get reported for spamming (you can do this easily but offsetting link tweets with another non-link tweet).
- It's ok to block "questionable" followers. This will mean different things to different people, just go with your gut.
I checked out http://www.buzzom.com and you can still bulk unfollow there :) ... you can only unfollow 25 at time but just keep clicking "more" until there isn't any more... then click "flush" again and you'll get the rest of the people who aren't following you. :)