Here are some ways that you can do to improve your studying and essentially improve your grades.
Study early.
If you start studying ahead of time, you will know the information fully. Cramming information can cause you to forget parts of what you were studying for.
Don't stay up all night.
If you stay up all night, you will be tired and sleepy. Lack of energy causes you to pay less attention and it will hurt your grade in the process. Once you think you know the information, go to bed and wake up fully rested.
Don't procrastinate.
Procrastinating is not a good idea when studying. It causes you to become more stressed and doesn't help as much as being prepared. Limited time gives you limited learning.
Go to your teacher.
Teachers ultimately know what is on their test. If you have a question or need help, go to them and they will guide the way. It is very helpful to get a full understanding and can give you a better study session overall.
Study with friends.
Different viewpoints and ways of studying can be shared when studying for tests with friends. This allows a way for the work to become more progressive and causes multiple people to ask different questions. Studying with friends also gives you an easier way to learn from someone other than the teacher.
Study in a place where you cannot be distracted.
Go to the library or somewhere quiet to get your work or studying done. It's easy to get distracted in a dorm due to the fact that you get more comfortable. It is better to be in a studious environment that allows you to truly focus on your work.