1. Stay calm. This part may be hard but just take a deep breath and try to gather your thoughts. Remember where you left all those textbooks and gather together some spare pieces of paper and pens. Highlighters and flashcards are also a good idea.
2. Once you have all your things together, make sure you find a nice quiet spot to study. Make sure its not too comfortable like your bed or the couch because you will risk the chance of falling asleep.
3. Open your textbooks and or notes and begin from the start. Don't focus on the little details though. Concentrate on the bigger picture, highlight the important facts that you think could possibly be on the test. Also remember to do the vocabulary. It will help your understanding if you know what a word means.
4. Write out important info or recite small bits out loud. This will help your brain process the material better. If you just skim your textbooks or notes you probably won't remember anything.
5. Make flash cards. This is a good way to quiz yourself and it also helps you process the information when you write out the flashcards and read them out loud.
6. After studying for a couple of hours, go to bed. If you stay up all night you will be so tired in the morning chances are you won't remember anything! Get up in the morning about 30-45 minutes earlier and familiarize yourself with the highlighted parts of your notes and textbooks. If you made flashcards go through them again.
7. Take a deep breath. Go through the information a couple of times on your way to school. Chances are if you paid attention in class and got in some good studying the night before you should be fine.
8. Ask your teacher for something to review for the test, maybe certain subjects. Look up anything possible online, and study a little in homeroom.
9. Also remember to go to bed at the appropriate time. You don't want to fall asleep in class. (ps: have a good breakfast so you feel healthy and not a have a stomach ache.)
10. If you have time, ask a friend or family member to quiz you. This will help you find out exactly what you do know, and what you need to read up on more.