Contact the professor who knew you well and whose courses you excelled in for a letter of recommendation; do not ask a professor who does not remember you, or even worse, did not like you. Visit the professor in person to ask him personally, or call him if necessary. Write him a request in a letter only if you are out of the area, such as you have moved to another state or the professor has taken a leave of absence; do not email him for the initial request as the email is more likely to be sent to a spam box, unread or ignored for lack of professionalism.
Introduce yourself to the professor and state what courses you took with her, as well as any other details regarding who you are, such as your major, course of study and future plans. Offer to refresh the professor's memory if she cannot recall who you are; if you have been out of school for more than a year, there is a chance she will not remember you. Ask the professor if she would feel comfortable giving you a letter of recommendation; do not continue with the request if the professor says "no." Have alternate professors in mind if one or more professor says "no."
Gather the information that is needed for your recommendation letter from the requesting institution after you identify who you will be providing you with a letter of recommendation so you can tailor the letter to his title. Most schools will have a standard letter of recommendation form that must be completed. Make a folder that includes all of the documents that you will need to send to the professor who is writing a letter of recommendation.
Include a professional letter from you that refreshes the professor of your request. Provide a one-page summary of your academic career, including extracurricular activities, all of the classes you excelled in that are related to the program you are applying for, achievement rewards and volunteer work, such as internships, along with a final paragraph reiterating your future plans and goals.
Include a standard form letter if required from the intended program in the folder. Make a note of when the letter of recommendation is due. Add a self-addressed stamped envelope to the school or program office where the sealed recommendation letter must be sent.
Send the package of documents approximately three to six months before the letter of recommendation is due to give the professor ample time to complete the request. Deliver the package of documents to the professor in person, so you know that he has received them. Alternatively, send it via a mail delivery service, so you can require a signature and date of receipt.
Give the professor one month after you know she has received the request before you contact her with a friendly reminder to ask if she has any questions regarding the request; this will give her a reminder in case she has not written the request without sounding pushy.
Check with the program that you are applying to one month before the letter of recommendation is due to see if it has been received. Contact the professor if it has not to ask him if he has had a chance to send it in; do not be annoying or you will risk a lost recommendation letter or even negative feedback.
Send the professor a thank-you note after the letter of recommendation is received. Contact the professor after you have been accepted into the program with a letter describing your new achievements. Keep in contact with the professor with a letter or phone call at least once a year -- she has had a part in your education and will feel appreciative to hear about your success.