in addition to what already been said, that you should follow the followers of authority accounts in your niche, you can follow people who tags their posts with niche-relevant hashtags and because you can follow only a limited amount of people, make every slot count, always take a look at the account before you follow anyone, is it active, does it look spammy? i configured my bot to follow people only who's active/tweeted in the last 7 days and have a different profile pic than the default avatar, i don't follow private accs and my followback ratio went up quite steeply, i still have customization options left like follower:following ratio, number of tweets
also, get your tags right when posting (i use ritetag and hastagify.me in table mode), you can get traffic from twitter search itself w/o following a single person, some of the posts i make with 0 follower accs get 1-2k impressions and generate clicks on the urls i post, you don't necessarily need followers to generate traffic on twitter