With testing season upon most students (Ohio Graduation Tests, Ohio Achievement Tests, SATs, PSATs, etc.) there is always additional pressures for students to feel successful.
What I always encourage my students to do when preparing for a larger exam is to break their study time into chunks. Younger students (middle schoolers) should be spending no more than 20-30 minutes at a time doing any type of "hard review". Allowing breaks and rewards (for example, watching their favorite TV show) can help motivate students who have difficulty concentrating. When students break up or chunk out their study times, it helps to break them of the habit of trying to cram everything in the night before. Additionally, this also helps the student to feel less pressure leading up to the test as far as performance.
Parents can help by discussing appropriate study habits, and encouraging students to set up an area in the home where they can quietly study away from noise and distractions. Parents also need to remember that a child's study should also be a time period, in which distractions coming from parents (chores to complete, questions, etc.) should be kept to a minimum.
Students should also understand that developing good study skills is a process and will take "trial and error" before finding the right amount of time, environment, study tips, etc. which is suitable for them. If a child doesn't do well on the very first exam in which they are trying new skills, as a parent, keep encouraging them to improve. Eventually, as good study habits form, the student will see progress on exam scores, and a renewed sense of accomplishment.