I cant stand engagement-farming, and even the phrase "follower" kinda rubs me the wring way... but how does a new user build up their network and start new conversations?
Discussion
If you see an interesting post, jump right in with your thoughts.
Post interesting stuff and use relevant hashtags so people searching for that kind of thing can find it (only a few clients support keyword search; I think all support hashtag search and some support hashtag following).