Two of the most important concepts for learning facts are active recall and spaced repetition. Rather than just spending more time studying to improve your learning (and grades!), spend your time more efficiently.
Active recall means stopping and asking yourself questions periodically. Reading an assignment straight through without stopping and then trying to remember what it was about is passive recall. You can greatly improve your retention if you pause from time to time and ask yourself what you just read. Stop at the end of each page or at section breaks and ask yourself questions about what you read.
Spaced repetition means repeating information at regular intervals. If you don’t use information, your brain will discard it as useless. When you regularly access information, however, your brain reinforces your memories. Go back over what you’ve previously read to keep from forgetting what you’ve already learned.
You can combine these two techniques by studying more frequently for shorter periods of time. Rather than studying for an hour (or more) two or three times a week, spend a few minutes every day. Instead of reading all of a chapter the night (or morning!) before it is due, start ahead of time and read a few pages a day, reviewing what you’ve already read. By the time tests and exams roll around, you’ll have a much stronger knowledge base than if you try to memorize everything at the last minute.
For a more detailed explanation of learning (and a longer list of rules), check out Supermemo’s 20 Rules of Formulating Knowledge. Anki is free spaced repetition software (i.e., automated flashcards) that allows you to create your own decks of cards. I’ve found it useful and recommend it as a supplement to course materials. It is also available as a web-only version limited to creating text-only decks. Memrise also uses spaced repetition along with game elements such as leaderboards, leveling up, daily goals, and streaks. It also has mobile apps for both Andriod and iOS. Although it focuses on language learning, there are courses for other subjects and you can create your own as well.
If you’re like pretty much every other human being on the planet, you’ve had bouts of procrastination. The Pomodoro Technique can help overcome if this is a problem for you. (More on the Pomodoro Technique from Lifehacker.) Melina Pierro’s comic “A Long Night Learning” explains this and other learning techniques in visual form:
If you’re still reading and you want to learn even more about learning, Coursera offers a free online course called Learning How to Learn: Powerful mental tools to help you master tough subjects that may be of interest.