You gotta post.
At least something. Three somethings ideally. They can just be really good shares, but ideally something that's your own take on something, even if the something is yourself. Or something you're sharing.
probably 70% of my follows on this website are from someone following me, and then me clicking into their profile and looking at their posts, finding the posts or the person's outlook interesting, and then I follow them. "Follow" should perhaps better be thought of as "subscribe" in the RSS sense.
doesn't need to be much, can even just be shares. but you gotta post something for people to grasp onto -- the timeline bandwidth is narrow, follows have a bit more weight here, talk about your stuff, even glancingly, and attract people with either similar interests, or who have the intent to read you
write posts -> find your people, the ancient blogging method in a nutshell
