Determine what you want to do for employment after college. You can take many online self-assessments to help you identify your interests, strengths and weaknesses in various career areas. (References 1-3.)
Take a course on major and minor planning at your school. Many universities offer this short course that is designed to help students narrow down their subjects of interest and decide on their academic area of concentration. (Reference 4.)
Research majors and minors offered at your school. Browse the undergraduate catalog and read the descriptions of the academic areas of interest. Examine the required and elective courses that are available, and determine the length of the program. You can also research majors on various Web sites, if you enter the keyword search in your Web browser: "What can I do with a major in ...." (Reference 5.)
Narrow your choices to two each for a major or a minor. Some students major in more than one subject, and many more minor in more than one area. Compare and contrast your choices and weigh them against your career aspirations in terms of cost of study versus career payoff. Also, consider if you are planning to go to graduate school, as certain master's and doctoral programs require specific undergraduate training.
Make a decision. You can do this alone, with the consultation of your family, with the help of a university career counselor or with your academic adviser.
Meet with your academic adviser, if necessary. Some schools require that students meet in person to declare their major, as the program adviser usually has to sign off on the student's paperwork. If you do not need to attend a meeting, make sure your adviser signs off on whatever forms you must complete and submit to declare formally your major and minor.