First; in your profile choose your followers.

In your followers menu choose one of ur follower and get in her/his account

In this account; choose his/her followers

In this menu follow only first 7 or 8 people to follow than chose another user in this 7 or 8 people and get in their followers menu and again only follow 7 or 8 people of his/her followers ...

Keep following first 7 or 8 followers and keep continue doing it, you will have 70% avarage people will follow you back.