When, I first started, I chose a few tags, and left it at that for ages. But more recently, I've been choosing more tags to follow. Whenever I add a tag to a story I'm publishing, I ask myself whether I would want to read any stories with that tag. If I do, I follow it.

But it's also possible that stories about Medium tend to be more popular because everyone on Medium is potentially interested in it. So we get recommended things that are generally popular on Medium, as well as specific recommendations based on our interests.