The following is an "open letter" from an anonymous UC-Berkeley professor to all undergraduates who need recommendation letters from faculty.
For many graduate and professional programs, letters of recommendation are one of the most important parts of your application. They can highlight your strengths, explain your weaknesses, and give a sense of you as a living, breathing human being. We (your professors) want to write you a good letter, but you can make it much easier for us to do so by noting the following advice:
First, choose faculty whom you know and who know you. In general, unless I know a student well I urge him/her to find someone else to write a letter of recommendation. If I don't know you, it is hard for me to write anything other than a lukewarm letter. In these competitive times a lukewarm letter is taken to mean that the professor wasn't impressed by you rather than what is really the case, namely that she didn't know you. If I suggest that you find someone else, please do not take this personally. It is my attempt to help you get access to the kind of strong letter that will get you admitted to the program of your choice.
Second, give all faculty the tools they need to write a strong letter. Especially at Berkeley where classes are so large, it never hurts to give the professor ammunition for a detailed, thoughtful letter. Such ammunition includes (but is not limited to):
a) your vita or resume b) your overall GPA c) your GPA in your major d) your personal statement e) the grade in the class or classes you took with me f) any particular glowing comments I may have written on your exams or papers g) your papers h) your current address and phone number as well as a permanent address and phone number of someone who will know how to reach you once you've moved.
Third, most graduate and professional schools prefer letters addressed to them directly. On occasion, a "generic" letter ("to whom it may concern") put on file in the Career Counseling office is seen as a lack of interest and/or commitment on the faculty person's part. Therefore, you will also need to give your recommenders the names, titles and specific addresses of the person to whom each letter is addressed. Here's a hint--it is often worth a phone call to find out who that person is because on occasion I know him or her and can point out how your interests intersect with their own. (At a minimum, I can use what I know about that specific department or program to highlight things I know about you which would make you a particularly good match for them.) Finally, if my letters need to be sent via snail-mail, be sure to give me pre-addressed, stamped envelopes for each.
Needless to say, a packet that contains this information and which is readable, neatly-typed and well organized maximizes the chances that I can write you a good letter.
Fourth, do allow for plenty of time to get these letters out. You may not believe it, but it's "normal" for me to have several hundred letters to get out in just a few weeks!
One final note: strange as it may sound, professors who write you letters of recommendation care about what happens to you. In the vast majority of cases, writing a letter of recommendation is like dropping letters in a bottle into the ocean: you never know who picks them up. Give your faculty a break, and drop them (us) a postcard, telling them what happened: it keeps us motivated to write students good letters even if your application was unsuccessful.
On behalf of your future letter-writers, thank you and good luck!
(a UC-Berkeley Professor)
Please see the additional resources¬†section for more advice on getting great letters of recommendation.