Employ active recall.
Active recall is a process through which you review material and then immediately check to determine how much of it you’ve remembered. Studies of student learning practices reveal that it is very important to memory formation to occasionally retrieve the information you’re trying to memorize. Using active recall will help you to strengthen memory and recall information.
Review the material you are studying.
Close the book or turn off the video or lecture, and write down or recite everything you remember from what you just reviewed.
Now, look at the material again. How much did you remember?