Exams are scary and make you feel really anxious, I'm telling you by experience. So, here a few tips for them:

1) I studied months in advance for my finals and it helped me hugely. It allowed me to study the whole suject calmly. Also, you can get help on a specific topic that you struggle with.

2) Okay, so focus mainly on studying. Study for a few hours with a little break in between them. After you have studied, you can go to social media or do whatever you will like to do.

3) I use music to focus on studying. It helps me focus. Also, I turn off my phone or the sounds of my phone so I don't get distracted. Once you are focus, it becomes more easier to study.

4) When I study, I use mind-maps/spider diagrams when studying for a test. It is helpful because you can see how each module connects with another one. I'm a visual learner, so these spider diagrams help me a lot. The are other types of learner like practical and the ones that listen. So, first you have to find which type of learner are you and which way of learning is the one that is best for you.

5) It is proven that when you practice your knowledge frequently, then you memorize it and get better at it. For example Math, with this subject you have to practice and practice and practice because that's the only way to get better. It can work for other classes too. You can check old questions from a previous test or ask for practice test to your teacher. You can also use the textbooks for this too. It really works. Remember also to read your previous exams to see what you did wrong and why, and what you can do to improve in this subject.