First things first I’ll try to update this list whenever I can. If people are inactive are not following back
please leave a comment below and I’ll have them removed.

Before following anyone look at their following to follower ratio. The number should be the similar or same.
If for example it’s clear that the user is either inactive, stopped following people back or is following people
just to unfollow them later then don’t follow that user. The best people to follow are the people that surpassed
the 5000 following and follower with a near 1:1 ratio.

Not only do those users follow back but most of the people who follow them also follow back as well. You can also use
a service like http://tweepi.com/ to find the people who did not follow you back.