If you are in middle school as my 13 year old is, it's important to establish routines that will serve you well in high school and college.These are not necessarily being taught but they include:
-taking excellent notes during class and while reading material
-keeping up with your review of new and old material in a course by reading your notes regularly
-making flash cards (on paper or digitally) to quiz yourself on vocabulary or other facts
-agree to be "study buddies" with at least 2 people to stay motivated when it's time to prepare for a test
-DO NOT try to cram the night before. Rather, set aside time for several days in a row (or even a week) before the big day to study in small chunks. Use those notes, make new ones to help your brain retain the information and study with one of your buddies. You will be less stressed and get better sleep AND be better prepared!