Before you approach anyone for a letter of reference, identify the number of people that you will need and the type of materials that you have to prepare. Doing so helps you figure out what each letter writer's role should be in relation to your application.
Application materials are your best ally in helping you choose the right letter writers. Some applications, for instance, encourage you to choose individuals who can speak to your teaching ability or character rather than those with the highest stature. Take this advice seriously.
Collectively, your letters should reflect a balanced picture of you. A Truman Scholarship winner from a few years ago obtained support letters from the following: a university program coordinator, an assistant professor of political science, and a Red Cross volunteer. If the person recommending you is expected to comment from a certain angle, be sure he or she knows this.
Avoid abruptly asking someone for a recommendation letter after class, in the hallway, or via e-mail. Instead, make an appointment with the individual to discuss whatever you are applying for and how he or she can help you. If possible, give the letter writer any materials that might help him or her write a more detailed letter, such as your resume or a draft of an application essay that you prepared.
If someone you ask for a letter seems to be saying "no" to you, seek someone else. The person may be inappropriate, too busy, or may not know you well enough to write you a good letter.
On an application form. you will usually be asked if you wish to waive - i.e. give up - your right to see the letter of reference. Do so. The letter writer will then be more comfortable and probably more genuine too. Also, many schools have a policy that a professor cannot reveal your grades or GPA in a letter of reference unless you give written permission. Those who review your application know your grades anyway, and the professor will probably want to discuss them for your benefit, either to applaud them or to help explain any inconsistencies. Therefore, provide the professor with a signed note granting him or her permission to discuss your grades.
This just takes some simple preparation. Be sure you know to whom the letter is to be addressed, and, as a courtesy, give the writer a stamped addressed envelope to mail it in. Provide an exact deadline for the letter's completion and gently remind the letter writer of it later if necessary.
When you apply for a job, graduate school, or a scholarship, you are confidently stepping up a rung on a long academic or professional ladder. Act accordingly by taking yourself and your supporters seriously. Do not undermine what you are applying for or be self-deprecating. Articulate some goals for yourself. Write them down if it helps. Respect and consider any coaching that is offered. Help the letter writer get to know you as a student and as a person.