Letters of recommendation provide colleges with a second opinion about your high school achievements and another view of who you are as a candidate and as a person.
Most colleges expect you to ask for letters of recommendation from your counselor and teachers. Choose and prepare your recommenders carefully. What they say about you (and how they say it) matters.
The application should clearly state how many letters are required and from whom. Typically, it's your high school counselor, one or two teachers, and possibly your principal. Some colleges ask for additional letters from non-academic sources, such as a pastor or coach, or even peers. Most of the time, colleges provide recommendation forms with their applications. Application services, like the Common App, provide their own recommendation forms.
You should select teachers with whom you have a positive relationship, who have taught you recently, and who have shown consistent interest in and appreciation for your work. Choosing a teacher simply because he or she is your favorite isn't necessarily a good idea. Choose teachers who made thoughtful comments on your work and have noticed how much academic progress you have made. The teacher should be able to provide specific, qualified examples of how you contributed to the class or excelled, and they should be able to talk about you as a person as well as a student.
Whomever you choose to write your letter, make sure they feel they can write you a strong and accurate recommendation. If the person isn’t sure and can’t give actual specifics about your performance as a student, then consider asking someone else. A lukewarm recommendation will do you more harm than good. Your recommender should be able to write about your contributions to the classroom environment as well as qualities that make you stand out as a student. This is especially important if you are applying to an Ivy League or other highly selective college.
Ask your recommenders as early as possible -- at least one month before your application deadline and preferably in the early fall. And don’t forget to follow up with them at least once before the letter is due to make sure they have everything they need.
The end of your junior year can be a good time to ask for recommendations. Your teachers and counselors have just taught or worked with you for an entire year or semester, and your achievements are fresh in their minds. They also have the entire summer to work on your recommendation, so they won’t feel rushed.
Supply them with any forms, instructions, and materials they need. It’s your job to do the heavy lifting for them. If you are using an application service, let them know what it is and that you will be "inviting" them through the service to complete a recommendation.
Admission officers have plenty of material about you already, so they usually don't want more letters than required. However, if there is a person who has a unique insight into your abilities, contact the admission office to see if it's okay to send an additional letter. It won't hurt to ask.
It might feel a little scary to ask a teacher or another adult for a college recommendation letter. But remember, many of the people you'll be asking consider these letters part of their job and want to see you succeed on your path to college. You might be surprised how happy they will be to help you.