What you must do to make your Twitter followers grow is to tweet a lot, but do not do it just to share your own content. You should be interactive in discussions related to your niche and use hashtags. Retweet the messages of the people you follow. All this will make you notice and people will be more willing to follow an active tweeter.
Not following in bulk is not a good idea. If you use software to do this, it will get the attention of Twitter, which does not approve of users making a massive deployment.
Doing a few follow-ups each day will not cause any harm and may only make you lose some of your followers, but if you win some new followers every day it will not be a problem.