Write, write, write. Although it should be obvious, many students fail to take good notes in class, and they miss a golden opportunity to retain the information that is being taught to them. Studies continually show that the act of writing (especially physically, with pen and paper, rather than on a laptop) cements information communicated to students in class. There are a multitude of distractions in the classroom, and writing keeps students focused on the voice of the teacher, helping them to retain far more of the information than they would just by listening alone. In a classroom full of other students, colors, lights and sounds, chunks of time go by after which many students find themselves thinking, "What was that? What did he just say?" In other words, they zone out. Writing what you hear cuts down the times that these occasions occur immensely.
Although taking great notes in class is a great beginning, there's more that can be done to send the information from the paper to the brain. At the end of the day, rewrite those notes. There are several reasons for this: 1) When you write notes quickly, there are often short abbreviations that you use just to keep up. A week or two down the line, you likely won't remember what those abbreviations mean. 2) Quick writing is also usually sloppy writing, just by its very nature. While the spoken words are still fresh in your mind, it's much easier to interpret your crazy chicken scratch. 3) Rewriting notes is almost like being able to be in the class a second time. Every time you rewrite a concept, you're furthering your ability to retain the information. I know several students that have taken to writing and rewriting and rewriting notes as a means for studying for an exam. It works well for them, because every time they write the same information down, the connections in the brain to the material get a little stronger.
So keep writing! Take good notes, rewrite those notes while they're still fresh, and save study time in the process. By the time you get to test time, you'll be amazed at how much of that information is still at your fingertips!