How do you research your follow sources?

[Antsmina]

Check this 3d

Super low follow back - how to increase?

Hey guys im runing couple accounts for about 2 month now and some one the accounts get 150-180 followers at the end of the month and some one then like 30-50… i see there people getting 500+ per month but i cant understand the problem. I think the problem is with my follow back ratio - how can i increase that? what filters should i use to use only high quality accounts? thanks for help!