like / comment on other people's pics, hashtag with popular tags, post good content
hard work will get you there; otherwise, use iMacros for a free solution
I had an account with 80k followers, never bought any (although a lot of ghosts.. as per usual), every picture I posted got to the popular page, the account got hacked and I'm restarting now. Now I have 19k followers, and working my way back up there. If you want pictures that will make it to the popular page almost every time, you're going to have to put in some work to get REAL followers -- ghost followers do nothing but fk up your chances because of instagram's algorithms.