There isn’t one magic thing, of course, but I would say that being an active learner is as important as anything else. What do I mean by being an active learner? I’ll give you an example. The textbook I use has lots of hypotheticals throughout each chapter. These are presented as a question, immediately followed by the answer and explanation. A passive learner will read the question, then read the answer (likely nodding because the explanation makes a lot of sense. An active learner will read the question, cover up the answer, think through the problem and mentally commit to an answer, and only then look at the book’s answer and explanation. It doesn’t matter if you get the answer right or wrong—in fact, research suggests that you might retain information better if you struggle with a problem, get the answer wrong, then internalize the correct answer. 

The same holds true for class. Don’t just sit passively listening to the class discussion (or worse, half listening). It’s tempting, when the professor calls on someone else, to breathe a sigh of relief and zone out. Resist that temptation! Take notes in class. Volunteer to answer questions. Ask your own questions. While you may take some flack if you constantly raise your hand and try to dominate class discussion, the days where it was cool to sit in quietly the back of the room should be behind you.

After class, do as many practice problems as you comfortably can. There are great reservoirs of practice problems available from many sources—some of which may be available for free depending on the arrangements your law school has made with the various publishers. One of my favorite source of civil procedure essay problems is Joseph Glannon’s Examples and Explanations, published by Aspen. For practice civil procedure multiple-choice questions, take a look at Mastering Multiple Choice for Federal Civil Procedure.