Well, there a few tricks to do this job. None of them will be substitute and can never replace the most 2 important things on Twitter: be original and follow the trends. From time to time you may found yourself in the position to start a trend, but this is another story.
Tweet often, but create space for reactions from your followers
Common sense says and some personal observation say that the number of followers is directly proportional with how active you are on Twitter. By tweeting you are making waves, you say something in the world of Twitter and sooner or later someone, somewhere, somehow will hear you and will follow you. Of course, remeber what I've said earlier about originality. If you tweet too regularly and about nothing that worths reading you risk losing your followers.
Be conversational
Twitter is a microblogging site but, after all, it's a social network. It became important because it offers an interesting method to communicate & interact with others: every time when you reply to someone and when he or she reply you everyone else see the conversation - your tweets are expodes to every user on Twitter, thousands of followers or potentionally followes that can responde to them.
Asking questions is one of the best way to start a conversation on Twitter, reply to the answers you get and put another questions. You may get your answers, but you may also get new followers.
Use the trends and start conversations using a theme or another. You may get attention from some people and they may start following you. That means you have to talk about things you are interestes and so are others.
DO NOT talk only about yourself. Nobody cares if you don't talk about something interesting... and you are not so interesting to most of the Twitter users in order to follow you.
If you decide to talk about youself (from time to time) be interesting and provocative.
Make a good Twitter avatar
The avatar is the the first thing people react to. So, put your best picture of you (especially when you are looking straight into the lens) or something really interesting (a design, a portrait or some picture) that define you best. Avoid funny images.
Write a good biography
Let people know you. Selective Twitter users will read the bio before deciding whether to follow you or to follow you back.
Add your Twitter account (and its link) to your email signature
Every time when you email anyone they’ll see that they can follow you on Twitter - there are good chances they are doing the same thing or/and they are not yet following you there.
List your account in Twitter directories
Directories like WeFollow and JustTweetIt are great places to provide other users with information about who you are and how to follow you on Twitter.
Post on your blog that you are tweeting
That part is available for bloggers only. There are official Twitter accounts for companies, they can also be promoted on the websites.
The source of the image is here.
