Learning experts have proposed several different schedules for reviewing study materials, but the following is one that works well for most people. Try it to see if it works for you, or whether it is more effective to introduce minor changes to the review schedule.
First, study what you can thoroughly learn in a 40-minute period. During this time keep your mind actively engaged in the material by making notes, asking yourself questions about it, speaking out loud, and making learning maps. Then take a five or ten minute break to do something completely different, preferably something which includes physical exercise and deep breathing.
After your ten-minute break, go back and review your original material and your written notes. Review for about five minutes. The next day review the material again for five minutes. A week later review it for five minutes. A month later review it for five minutes.
If you need to remember the information longer, review it for five minutes after two months, and then again after six months.
Your review will be even more successful if you speak your thoughts out loud. You can say a verbal summary out loud to yourself, or you can speak the summary to someone else.
Each time you repeat the same physical action, or review the same study material, there are chemical changes that take place at the synapses between your brain cells, making it easier for the signal to go through the next time you repeat that thought or action. That is why review and repetition help fix acquired skills and knowledge in your brain.
Saying the material out loud, or writing out a few notes again will involve more of your brain cells in the process of remembering.