1. Tweet or else you don't exist ;-), I normally clean up contacts on both follow and followers list. If I don't know you, you follow me and all you say on your profile is "Hi", "I came back from n-hangout" then I block you. If I follow you and you don't say much ever I un-follow you.
2. Have conversations , I follow very few people who don't engage in conversations. Conversations need not be real time but nobody likes monologue. So if you are a one-way broadcast marketer or a social media twitterfly and don't engage in conversations then it is likely I won't follow you.
3. Clean up of follow lists Nice and clean follow list. I block all spammers or one way broadcasters from my follow lists. There are interesting people in my follow list who I try to have conversations with. Even more important for me is that my followers browsing through my followed by list find those interesting people.
4. Vary of large numbers Normally I wouldn't follow you if you follow 100s of people and 100s of people follow you back. Which means that we won't have much conversation space. Again there are exceptions to the rule.
Connect with me at @tarundua81