I used to build followers on Tmblr, Twitter, and Pinterest the old school way of manually following people interested in the same things I do and hoping they follow back and got maybe a 5-40% follow back rate depending on how good my content looked (search Youtube for Jay Wessman for good tutorials on this.) Unfortunately, I started getting my accounts suspended or banned when I started trying to automate following using python. I like to stay cautious with some of these and follow manually but rely on python to scrape lists of potential people to follow and build a simple UI where i can quickly click away.

I’m not too familiar with Instagram but it would also serve you well to post new content on a regular basis to your followers (they’ll share them out, attracting more followers if it’s good) and i usually use a Tumblr account and python to queue it up in Tumblr then connect the tumblr to the target platform i want my posts to drip out onto over time.