What does it take to get into an IVY Leauge?

So as high school starts soon, I was wondering what it would take to get into an IVY. I will be attending a good public high school (previously in private) with an IB and AP program. Would going to a public school hurt? In terms of academics, what advice would you give? Also in terms of extra curriculars, what does it take to get into an IVY?

I know that there is no “cookie-cutter” method to get into an IVY, but what did people do to go there is all I’m asking, as I would like some ideas on EC’s I should do. I already do have a sport, so that shouldn’t be a problem.

Also, please make this merritt-based only. (ex: no legacies, donors, etc.)

FAQ: http://talk.qa.collegeconfidential.com/what-my-chances/1525399-if-you-are-asking-for-your-chances-to-ivies-and-other-top-schools.html#latest

Why is this a new thread?

http://talk.qa.collegeconfidential.com/what-my-chances/2095312-generic-chance-answer-for-super-selective-colleges-p1.html

MODERTOR’S NOTE: Closing since users have posted two good threads as resources.