What extra curricular activities do you recommend to people who would like to get into Duke? Do you have to be from a super super nice school and be Ivy league bond?
For extracurricular activities, I think you shouldn't focus primarily on the exact activities you should participate in. Rather, focus on some aspect that you want to explore and build on that. I like dance and I am not that great of a leader, so I joined Dance Troupe at my school and I eventually became a Grade Level Captain. I had more responsibilities and I learned leadership skills. That's just one example.
Really, I would just focus on finding an activity (or activities) that interests you and you want to try out. But here's the catch: let it be an activity you know you'll be committed to. Don't try out activities if you're not going to stick to them. It may seem cool that you participated in many activities, but will you be able to say something you liked from participating in them? That's really the important thing.
And no, you don't have to be from a super super nice school. I went to a private school, but in my school's history only one other student had enrolled at Duke; she's currently a junior and she was the Dance Troupe Head Captain when I entered Dance Troupe. Other girls have been accepted to Duke, but they didn't enroll. I admit, I was somewhat of a strong student academically but I feel that I could have been better. So yes, I tried some Ivy Leagues (didn't work out, obviously) but I don't regret it. You don't have to be Ivy League bound, and I don't think you should worry about that. For some students, it may be helpful that they are a legacy - their parents went to the school, their grandparents went, uncles, aunts, so on and so forth. Me, I'm first in my family to graduate from high school, as in didn't drop out and go back to school (that's a different story), and the second cousin to go to college straight out of high school (a first cousin of mine is in her junior year at UPenn).
In reality, you just have to be dedicated to your studies and your activities. Schools like Duke can't ask for more than that. If you show that you are dedicated and hard-working, odds may be in your favor. I'm just speaking from a non-administrative standpoint.
I hope this helps. Feel free to ask me any questions you have.
-Cameron Crazie 2015Go Blue Devils!