An interesting thing is that different people learning the same material can spend the same part of time, learn in the similar conditions, and then get different results. It points to students' different methods of studying.

Students that use better study methods and strategies show higher results on their exams.
There is no way to make people the same. Everyone is different, different methods are effective for different people. It is possible to improve your current studying techniques.
The best is to review the material right after you've learned it and it's still fresh in your memory (after class, if you prepare on the courses or with coach).
Concerning any exam, don't leave your preparation for the night before the test. Better is to space out your studying, review class materials at least several times a week, focusing on one topic at a time. 
Have all of your study material in front of you: lecture notes, course textbooks, study guides and any other relevant material. 
Try to study in comfortable and quiet place. Care so that lighting was good and distractions not great. Avoid your bed, since it is too comfortable place to lie down and take a nap. 
Start with the most important information. 
First learn the general concepts; when you see the general picture, get down to details.
Try to write down a summary of the important ideas, so you can later review the shortened version of material.
Take short breaks frequently. Give your brain time to rest and your memory to retain the information.
If you study by little portions every day, you'll get better result than everything at once. By studying everyday, the material will stay in your long-term memory. The last moment studied material will remain in your memory for a short period and then you will easily forget it. 
Try to understand the material well, not trying just to memorize everything.
If you study in a group, choose only serious about the test people to communicate with. 
It is helpful to test yourself (or ask someone to test you) before the real test to know your weak and strong areas. You can use sample tasks in Internet, review questions in special books or practice tests the teacher may give out as well as other materials. 
If you feel too bored and tired, listening to relaxing music (classical music or jazz) on a low volume can relieve you. 
Try not to study later your usual time you go to sleep, as you may fall asleep or be tempted to go to sleep, instead of studying. You will feel uncomfortable and learning effectiveness will be too law anyway. Sometimes it is better to sleep for a while and get up early in the morning to study. Your strength will be fresher in the morning than at night.