Ask for Recommendations
Recommendations allow admissions officers to see how you are perceived by your teachers. To get strong letters from your teachers, build strong relationships with them early and ask them in advance.
Most students choose teachers from their junior year to write their letters of recommendation, so work to build relationships with those teachers.
Seek advice or help on important tests and papers and show that you are interested by participating in class.
However, do not just pick a teacher who gave you a good grade. Sometimes a teacher who has seen you struggle but work hard can write a far more compelling letter.
Give the teachers that you wish to write letters for you plenty of advance notice. Think about asking your teachers before the summer so that they have time to formulate a strong letter.
Also, explain to them why you would like them to write a recommendation for you, and provide some information about yourself that they may not know, such as your activities or aspirations.
Finally, make sure to write thank-you notes to the teachers who wrote your letters. You should be very appreciative of the time and effort they've taken to write about your abilities.