It makes sense that teachers can write better letters for students they know well so the way to get the best recommendation is to get to know your teachers. Try the following:
• If you have a grasp of the material being taught, speak up in class. Answer questions posed by your teacher and/or your classmates. Volunteering your knowledge allows a teacher to see you’re really getting it and, in addition to helping your classmates, you will learn more as well by the way people respond to your comments.
• If you’re having trouble understanding something, ask questions. If you’re not comfortable asking them in class, approach your teacher outside of class. Most teachers want to help you but they can’t if they don’t know you need help. Some of the best letters of recommendation come from teachers of students who may not have received a strong grade in a class but who worked hard, sought help, and never gave up.
• If you have an interest in a club or activity that a teacher of yours is a part of, get involved. This allows you to have an outlet for your talent and also allows your teacher to see you in a different way. The best letters of recommendation include information about your scholarship, classroom behavior, ability and willingness to seek help, and information about what kind of person you are in other contexts as well. The more ways a teacher has to see who you are, the better the letter he or she can write for you.
You should identify teachers you get along with and who you may want to ask to write a letter for you by the mid-point of your junior year. If you haven’t already been doing so, follow the above steps to begin to cultivate a relationship. Be genuine: your primary goal is to understand the material and help your class become a stronger, more cohesive learning environment. A great letter of recommendation will flow naturally from your efforts. Once you feel you’ve established a solid relationship with that teacher, ask if he or she would be willing to write on your behalf. Doing this with at least a month left in your junior year will give your teacher plenty of time to really observe you in the classroom setting and, if necessary, gather more information for the letter. It will also give the teacher the option to write the letter on his or her own pace and time frame.
When you ask your teacher for the letter (do so in person, btw), make sure you have a resume to provide. This will ensure your teacher doesn’t forget anything important about you. Mention anything specific you hope the teacher will include in the letter (perhaps a particular project you did in class or a problem you helped solve).