I whittled my follow list down to 200 and so active accounts so that new users can use it as a starting point to fill their feed with good content. It would also be useful in your situation. Look through it and see who you're not following right now.
Discussion
I wish there was a followstr or something that let me see who people i follow were following and let me quickly select them to follow.
last site that did this was nostrgram.co and its still after all these months so far ahead in features but defunkt.