I only sporadically think of who I'm following, and the recent addition of showing how many posts of someone you have shared when you hover over their name has really helped. I just look at my feed and see the people who have grey or green usernames and see if I'm sharing a lot of them. If I do I'll likely follow them and then if I see stuff from them that I think I could do without I'll re-evaluate whether or not I should unfollow them or just ignore a tag or two.

That isn't the only reason I follow people, though. I also seek out users who provide perspectives that I don't understand or perhaps agree with. It can be harder to find these people; I usually find them when reading comments.

For instance, recently I've been following every writing tag and writer I can find on hubski. I'm not a huge poetry guy, or even a fiction guy, but I'm rather jealous of those who write well and envy those who have the discipline to write better. Eventually I'll probably prune some of those users and tags from my feed and the end result will be better than I started out with.