Ok so i have 2 accounts A and B in same niche (for example soft drinks). Account A has red soft drinks theme and account B has blue soft drinks theme. Before i did this they followed different accounts followers with followback 10-30%. With follow method account A totaly has 4k followers and what i know about them is that they niche related and follows back brand accounts that follows them. So i scraped all of them added some filters like users posted in last 10 days etc. and added that list to my B account scraped users for following list. This is how i got 70% followback ratio on account B for some time. Keep in mind that this is one time thing and if you add that list to more and more accounts % will drop. Im using followliker.