They report being better able to understand the material when they hear it rather than simply reading it. If there is supplemental instruction provided in a course you are taking, do attend those sessions. They give you an opportunity to review and clarify material you have covered in class. Your understanding of new material depends a great deal on how much you already know about the subject. The more you increase your basic knowledge, the easier it is to build new knowledge on this background.
Some students find it helpful to find another text on the same material.
Reading about the same concept from a range of sources can expand your understanding by allowing you to view it from a couple of author's perspectives. Mnemonic devices can be useful when you need to remember a list of facts, or steps in a procedure. Some Men Hate Each Other to remember their order. Once you memorize them, write them on the back of your test before you even look at the test. Refer to the list when needed.