Start early in preparing for the admission application. Each college application is unique in its way. To make yours stand out, spend quality time preparing each application. Often, students make the mistake of submitting generic essays with each application. Instead, do thorough research of each university you are applying to. Attend university open houses and/or high school summer programs in those universities. Go to the university website and look into the different general education core programs, academic offerings and resources the school offers. Discuss in your essays on how you will fit in to the university or why a certain university may want to give you an opportunity to attend.
Demonstrate how you have achieved above and beyond in both academics and extracurricular activities using the resources available to you. To stand out, emphasize how you use your resources and how you have made a difference in yourself and/or in your community. Since candidates come from different demographic and geographic backgrounds, it is difficult to compare candidates based on scores alone. Admission officers often look into personal attributes to determine candidates' maturity and personality. So, to make your application stand out, include how you find and use resources to make an impact in your community -- don't just list clubs you are in.
Score well in standardized tests and Advanced Placement classes. Though test scores are not the only item admission officers consider in evaluating candidates, you want to score as high as you can so that you will be put in the upper tiers of the candidate pools. Most Ivy League applicants score at or near to the 99th percentile in these tests. Only a handful of students who don't score very high will get accepted based on achievements in other categories. Take the test only when you are ready. AP classes also demonstrate your ability to do well in college coursework. If possible, start taking AP classes in your junior year so that you can show the scores in your college application.
Obtain recommendation letters from people who know you well. Ask teachers who can speak about your intellectual and social abilities to write your recommendation letters. For example, if you are the president of the math team and have consistently assisted in hosting activities and represented the school in various activities, the math team adviser will be able to discuss a history of your contributions and personal attributes in these letters. When you ask teachers to write you a recommendation letter, give them your personal statement so that they can recall and relate to you. It is especially important if you haven't had that teacher for the past semester or two. The recommendation letter is as important as other parts of the application. A strong letter will help you stand out in the pool of applicants.