By planning well, you work step by step towards a test or product, taking into account some facts about effective learning. For learning, it is important to set clear goals, review things regularly so you forget them less quickly, and take a break after 30 minutes of studying. It is most effective to learn a little bit every day. Additionally, it is useful to start after a fixed moment. For example: 'after dinner on Monday, then I will do my English homework.' This way, you can make the following schedule. If you have a test on March 20, then you want to review mainly on March 19, review and learn the last new things on March 18, review and learn a part on March 17, etc. Each day of studying then consists of reviewing the past few days and learning something new. It is also good to make practice questions in between, so you can see what you do or do not understand (and in a subject like Mathematics, you learn precisely by doing a lot of problems). A part of the example schedule:
Bjork, R. A., Dunlosky, J., & Kornell, N. (2013). Self-regulated learning: Beliefs, techniques, and illusions. Annual review of psychology, 64, 417-444.
Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students’ learning with effective learning techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4-58.
Hartwig, M. K., & Dunlosky, J. (2012). Study strategies of college students: Are self-testing and scheduling related to achievement?. Psychonomic Bulletin & Review, 19(1), 126-134.