Following the right people on Twitter is important, but so is unfollowing the wrong people. If you are leading a busy life, you don't have time to read thousands of tweets per day, particularly when too many tweets come from the same users. Here are some tips that will help you identify who you should unfollow.
Use Twitter Lists. Create lists so that you can categorize and keep track of people who post similar content. There is no need to continue to follow these individuals in your main feed. You can keep certain users on lists and you can check them whenever you want. This will ensure that important tweets don't get lost in the feed.
Watch who is unfollowing you. Quitter is a Twitter tool that lets you know who stops following you and when via email alerts. It gives you a chance to consider whether or not you want to continue to follow those people or not.
Drop inactive accounts. Some people don't really tweet much and therefore don't need to be in your main feed. If you notice that you are following someone that hasn't used their account in months, unfollowing them is a good idea and they probably won't even notice.
Monitor your follower-to-following ratio. If you are following a lot more people than are following you, the likelihood of more people following you will be very low. Try to follow a lower number of people than are following you. This way you will not look like a spammer.
Generally, you shouldn't just follow anyone on Twitter. It's all about building relationships and staying informed. Take as much care in choosing who you stop following as you do when you choose the users that you will follow.