Practice in class. Get some oxygen to that expensive brain of yours. Water Toss an Aquafina in your backpack. Drink less soda, keep the calcium you have. You can live about a month without food, but only about a week without water.
Nutrition Eat balanced meals, regular meals.
Don't let your projects and tests make you miss meals. Make smart choices, apples over Cheeto's. It's good for more than just your skin. Don't overdo it in the summer, don't skip it in the winter. The 'Just Say NO' list.