Study. And then study more. Initially you'll forget more than you remember. Move the information from your short-term memory to your long-term memory by immersing yourself in the material. Write the most important facts on note cards and read them throughout the day. Post information on your refrigerator door, your bathroom mirror, on your dashboard.
Associate the facts with memories. Allow what you're trying to remember piggyback off what you do remember. The memories don't have be related to the study material; you can associate the information with TV shows, names of your best friends, foods, songs, movies, pet names, whatever comes to mind.
Review the material often. Read notes right after class to keep the information fresh in your mind. Write concepts on your own from memory without reading your notes or looking in the text. Explain concepts to other people; it is said you truly know something once you can teach it. Study in groups so you and your classmates can help fill holes on each other's understanding.
Repeat the information often. Repetition ingrains memories in our minds. It's why you still remember the alphabet song, nursery rhymes or "The Star-Spangled Banner." Alternate between studying quietly and saying the information out loud; put it to a melody or a poem. Find words that rhyme with terms you're trying to remember.
Take breaks. Our minds perform better when they're refreshed. Sleep when you're tired, eat when you're hungry. Take naps during study sessions if you feel your eyes closing. As little as 15 minutes can refresh and energize you; you might wake up understanding concepts that previously confused you.
Decide to remember. When you sit down to study, tell yourself "I am going to remember everything I need to remember." Your subconscious mind, summoned by the intent to remember, will activate powers of memory you didn't know you had.