<p>Oh, to answer the OP, though I’m not currently attending:</p>
<p>1) Test scores and grades, took the hardest classes available at my high school (which was only 6 APs to give you an idea), recommendations and essays hopefully showed that I was sincerely interested in science.
2) Aeronautics (which is what I came in planning to do), History (added for fun in my sophomore year).
3) Do the things you enjoy. I spent much more time on music activities in high school than I did on math/science stuff (although I also did some of those things of course) and I don’t think it hurt me a bit.</p>