1. Stay on message
   pick your niche and stick with it - people interested in your niche will find you
2. Only follow people who have more followers than they themselves follow
   People retweet those they follow - a low following-to-follower ration indicates they're picky about who they follow (and therefore retweet)
3. Don't reciprocal follow anyone who follows you
   Most follows are junk. Auto-following jerks who've latched onto a keyword. Don't give them credibility.
4. Unfollow anyone who spams 40 posts a minute
   There's no way they're reading what they're polluting your inbox with - zero quality = no follow
5. Don't follow those who don't retweet
   If they're not retweeting, they're not reading. Specifically, they're not reading you!
6. Only follow those who fit your niche
   You retweet those that you follow - if you want to stay on topic, only follow those are worth retweeting
7. Challenge, converse and retweet
   Get into a dialogue with those you follow if you want them to follow you back

Follow these rules (and be interesting!) and you'll slowly but surely amass a following of interesting, niche-specific followers!