There is no cookie-cutter way to ensure admission to the school of your choice. While having good grades, or even being at the top of your class, will certainly improve your chances of getting accepted into the best private schools or the best colleges in the US, ultimately, the competitive nature of the admissions process will see you facing off against thousands of students who will also boast of a good portfolio. The key is to differentiate yourself from the other applicants and make admissions officers see you as a good fit for their school.