If you are looking for increasing your twitter followers/friends then here are some tips which if you follow, you can for sure gain good number of followers in a short span of time and build a bigger network :

1. Register and start following the top bloggers or top twitter users who are in your business
2. Offer breaking news within your twitter network which can be ReTweeted[RT] and can help you in becoming famous within a short span of time.
3. Fill your profile under your settings tab and try to fit your profile under the 160 characters limit[One Line Bio]
4. Upload unique images using TwitPic, and tweet about them, which are worth retweeting.
5. Start Twitter contests among your blog/website readers with prizes given randomly.
6. Advertise on TwitterCounter which is a effective way to gain followers quickly.
7. Link to your Twitter Profile from all the available locations like your Instant Messenger Status, Email Signatures, About Page on your Blogs, digg profile page, facebook, myspace, linkedin etc
8. Ask Questions on Twitter, which can be answered by many and in return they would even follow you for building a network with you.
9. Post about job updates or openings at different companies and employees looking for jobs would follow you.
10. Use Hashtags(#) for particular keywords which are sometimes searched more than the normal keywords in twitter search engine.
11. Mr. Tweet – A personal twitter assistant. Follow that bot and the tool suggests the best people who can come under your network, and make good conversations with them, and this in-turn gets you more followers.
12. Show off your follower count and rankings by displaying Twittercounter, Twitter Grader buttons in your blogs.
13. Be active always. If you can’t, Tweet Later can help you schedule tweets for you when you are busy or not connected. This shows your continued presence on twitter, which followers expect from you.