The average Twitter user has 208 followers
Post quality content
The most important rule involves posting high-quality content you know your followers will find useful. If you come across a web page or tool you find useful, share it with your followers. Chances are, they’ll find it just as handy.
Be sure to retweet anything you feel is relevant, and credit your sources whenever possible. Randomly posting poor or irrelevant content will quickly have your followers reaching for the unfollow button.
Post relevant content
Keep it relevant. Your followers followed you because they like your business, the service you offer, and the content and subjects you tweet about. This doesn't necessarily mean you can’t tweet about things outside of your industry, but don't lose touch with your business goals or your main objective on Twitter, which is to cater to your followers and customers.
If you tweet only once a week, your followers might forget you are on Twitter, or may not see the point in following you. Not tweeting over a period of months may even result in people thinking your business has slowed down, or worse still, that it no longer operates.
There is no correct number of times to tweet in a day or week, but try to tweet daily. Just engage, and contribute to the conversation.
Use hashtags where appropriate
Hashtags are a great way of sparking a debate and attracting relevant participants to the conversation. Don't overdo it, though - a tweet that is filled with hashtags can be hard to read, and just looks spammy.
Link to your Twitter account
Always make sure have a link to your Twitter account placed prominently on your website. This is one of the simplest ways to build followers, because regular visitors to your site who also use Twitter are very likely to start following you.
Also, if you’re not lucky enough to have your Twitter account verified by Twitter, adding your Twitter @username to your website is a good way to assure your customers that it really is you on Twitter, and not an imposter.!
Quality over quantity
Building your number of followers takes time. Accounts with very few tweets will have very few followers. The more often you post, the more likely people will be to follow you.
However, while you should keep track of the number of people who follow you, you shouldn't forget that quality and relevance to your followers is more important than sheer quantity.