Be active in class
Participating in class can help you remember material better. The more you involve different senses, the more connections you build to the information, and the easier it will be to recall when you need it.
Keep up with assigned readings throughout the course so that there will be no need to cram. To avoid completely re-reading the text, prepare it for review by judiciously underlining key words and phrases, then outlining the underlined material. Learn more about study habits to adopt and study habits to avoid.
Review, review, review
Review class notes, homework, and reading assignments so that by the time exams come along, the material from early in the semester will not be forgotten. Set aside 15-30 minutes for each subject every week to review. If we do not review material, it leaves our memory very quickly. In the first 24 hours alone, we forget about 30% of what we learned. We can see the effects of this in the Curve of Forgetting.
Connect with your instructor
Using instructor office hours (in-person or online) is a good habit start. Ask 'how do you think through this question or problem?' to gain insight in how knowledge is applied. Ask questions about the material you do not understand. Find out why you lost points on an assignment or quiz to better understand what is expected in a correct answer. You need to really understand before you will remember.