Future employers sometimes require letters of recommendation, and grad schools always do. Your professors can write letters for you. To write a good letter, the professor must know more about you than the grade you received in class. Your professor will be favorably impressed if you make efforts to be an active participant in class, think about the class material outside of class and ask interesting questions, or actively help students who are struggling with the class material. Well written, thoughtful papers that show special care and effort also impress professors.
To get the most meaningful letters, try to get to know a few of your professors fairly well. You can get to know professors better by visiting them during office hours. You are not intruding. Ask for career advice, or about topics in which you sincerely share an interest. The very best way to get to know professors well is to work with them on projects, either theirs or yours. Professors actively involved in research are usually very grateful for assistance, and perhaps can even pay for it. Most professors are happy to work with students who want to do Independent Study that goes beyond material covered in regular classes, if the project is meaningful.
Provide your references with relevant information about yourself, including
In addition, figure out ways to help your letter writers address the skills, knowledge, and qualities sought by the people who will be reading the letters, as described in How to make yourself more attractive to grad schools or How to make yourself more attractive to employers.
Before giving the required forms to your references