Go to class and pay attention. This is the most important thing you can do. You'll hear at least 80 percent of what you need to know in the lectures. Going to class, even if you don't feel like it, will save you time studying and give you the confidence to know that passing is possible.
Make friends and form study groups early in the semester. This should be easy if you're taking the corresponding lab; chances are that your lab partners need a little extra motivation, too. Keep group times on a regular schedule so that everyone knows when to meet.
Understand the logic, but don't attempt to memorize physics. Once the "big picture" clicks in your head, and it will, every physics class from then on will make tremendous sense, and you may even come to enjoy the subject. But if all you're doing is regurgitating formulae, the "click" may never come.
Teach the material. Practice by explaining physics problems to someone who doesn't understand them. Teaching someone else is the best way to solidify the material in your mind. Let someone else teach you how to do problems you don't understand, and then pass the information along.
Complete those practice problems until the end even if you don't think you need to, and check your final answers. We all have brain freezes sometimes, and practice can help you identify any problems you're having with your math.
Read all the exam questions before starting the test. Don't get intimidated by those you don't understand at first. Complete the problems you do know, then stop, relax and let the solutions come to you. Try not to look at the clock when you're trying to remember how to do the last few problems. Keep telling yourself, "I know this."
Identify the unknown in each problem, and underline it with a double line. The unknown is the quantity the problem is asking you to figure out. Underline all of the given data with a single line. Make a sketch or a graph. Even if you don't know how to solve a problem at first, it will likely come to you as you're drawing it out.