Another thing apart from just following people that can also ensure that others follow you is to create contents. Become a voice of some sort for a cause. A subject that you regularly tweet about; something for which your name can become synonymous.
Apart from coming up with your own content all the time, you could also use tweets by other people to boost your own credibility as a force to be reckoned with on such subject. This calls for discipline and paying the price to read and search out relevant information on your part.
If you are an accountant for example, do you know any latest information coming out from ICAN, the body that guides the practice of professional accounting in Nigeria? Tweet that or retweet their tweet. So you must be on the lookout for relevant information in your field and tweet them or as the case may be, retweet them.