What should I do during my junior year?

Currently I am a sophomore in high school and I have a week until I graduate. I was just wondering what should I do during my junior year to help improve my chances of getting into University of Washington, University of Michigan, UC colleges, Duke, Northwestern, and other great selective colleges. Right now I have a 3.7 GPA, good extracurriculars, and I signed up for 6 IB classes next year.

Just keep your grades up, test above a 1400 on the SAT, and increase your participation in your ECs.

Thanks for information!