Follow other people, talk to them, and hope that they follow you back. How to reply to a tweet: @username Message.
Check out my most recent blog post here: Twitter: Three tools you should be using on a few tools to help you get followers.
Hover over a tweet and click the reply icon.
My Awesome Signature is awesome...
You can get good scripts from web. If you are able to create a tool yourself that will be the best thing. Other wise you can depend available tools like humming bird and twitlink but they all are paid services.
Follow me on Twitter: @hendricius
Simple way is, follow others and they will follow you!
The tool I personally like, is InRev. You can easily: Follow, Flush & Reciprocate other Twitter users. For some accounts it's usefull to have thousands of followers, no matter who or what it is (For example my Adult Twitter Account).
Next what I do is:
Grow until you reach the daily limit. Next day do the same and the day after that too (3 days).
The fourth day, you flush all users that aren't following you back (flush = users you follow but aren't following back). And sometimes it's also cool to reciprocate although I'm not doing it that much lately..
If you are looking for just looking for fun then jeep adding as much as users you can . 40% of them automatically follow you .
But if you want it for business purpose than keep tweeting good knowledge links and information . It will take time but you can gain good targeted followers .