Preparing for a math test starts when you first learn the material. Make sure you keep up with your homework and understand concepts as they are taught. To study for the test, review your class notes, do practice problems and write down formulas you need to memorize.
Take detailed notes as you learn and keep up with the homework. If you learn the concepts well the first time, you only need to review instead of learning from scratch. Keep all of your notes and homework organized as you go so you can find everything easily later.
When it's time to study, go over your lecture notes and make sure you remember all of the concepts. Do several practice problems: start section by section, and then mix up the concepts and make sure you can still do the problems. Check your work on the first few problems to make sure you're doing them right before finishing the set. Try a timed practice test, using review problems your teacher handed out or a chapter test in your textbook.
Write down anything you need to memorize, especially formulas, even if you can't have that cheat sheet on your test. Repetition is key, so write out each formula several times until you know it by heart.
Study with a friend. If you're stuck, your friend can help, and if you need to teach something to your friend, you'll understand it even better.