Writing letters of recommendation is one of the central duties of my profession and I take it very seriously. Here's what I need to write a letter for you. Good luck!
Procedural aspects:
Contact me via email to request a letter of recommendation at least 5 weeks in advance of your first deadline.
If I don't know you or your work very well, I may suggest that we meet, either in person or over phone, to discuss if I am a good choice for you. If I feel that I am not able to write a strong or compelling letter, I promise to tell you. This reinforces the 5 week deadline above - you will want to have time to find a replacement.
If I agree to write a letter please send all supporting documents and a list of programs/jobs where you will apply with deadlines (I used a two column list to do this as an undergraduate) one month before the deadline.
In a single PDF file, please send me the following documents and answers to the questions.
Questions:
What is your name and preferred personal pronoun?
In what capacity and for how long have we known each other?
What aspects of yourself should the letter address? What do you self-assess as your strengths as a mathematician?
Are there highlights on your CV that I should pay special attention to? Are there circumstances I should be aware of in reading your file?
What are your long term goals? If you are applying to graduate school, do you have an area of mathematics that you are especially interested in?
If you are applying for an industry job, what aspects of your being should I address?
Documents:
CV
Undergraduate Students: transcript (an unofficial one is perfectly fine)
Undergraduate Students: a list of your mathematics classes and a short description of the classes themselves (i.e. don't make me look up what Math 380 at your university is, just tell me you took abstract algebra)
Research statement.
copies of any papers or theses you have written, or working links.
If your letter has not been submitted within 24 hours of a deadline, please send me a reminder. Also, sometimes graduate school applications do not request letters from recommenders until the applicant has submitted the application. Please do not put me in a situation where being away from email for 24 hours will make me miss a deadline.