Break your study time into blocks of 20 to 50 minutes. Go on a walk or bike ride in between to help you relax and focus while studying. Know your personal concentration limits and recognize when you become restless. Don't fight it; work with it.
Choose a study location free of distractions. Try to create an environment similar to that of the test itself: If you'll be in a room full of other students, but one that is quiet, try studying in the library. This tip not only helps you to focus, but also trains your brain to perform under test-like conditions.
Prioritize your assignments and study needs to allow you to spend more time where you really need it. Create a planner to help you organize daily, weekly and monthly study tasks. Stay on top of things and you'll have much more free time--and less stress.
Review material briefly before and after class to help reinforce learning. This simple tip will save you study time later.
Study early in the day when possible. Everyone is different, but, in general, it is easier to concentrate early in the day. You might get as much studying done in half the time you would spend studying late at night.