This ISN'T just for the maker of this thread, if you're having trouble in school, read!
Now, I'm an A student, and I really don't do all that much, but here's what I suggest:
1. Eat breakfast. Look at your report card, if you don't eat breakfast, your morning classes will suffer.
2. Have a scheduled homework time. Now I know this sounds harsh, but schedule 1-2 hours every day to do homework. Do it to full extent. But heres the thing, finish, DONT! Not until your ellotted time is finished. Read, elaborate, anything subjected to learning. I do two hours every night from 6-8 doing homework. It's not harsh, plus it's great when going into a harder year at school, new semester, and even prepare you for College 7 hour Homework sessions. (Yes, college takes about 5 hours of classes, and the rest of the afternoon averages clock into 7 hours. Correct me if wrong)
3. MOTIVATE YOURSELF! School feels duller the moment you have negative thoughts. Now people say they hate school, they're just annoyed of having 8 hours taken from them to sit in a classroom. But the truth is, people are just negative about school. Make a positive emphasis of school. If you like gym, then be prepared to crush the other team, if you have a class your good at or enjoy, be prepared for it.
4. Get your parents involved . Sullen teenagers probably don't care for being with their parents that often, but let them get into your school life, especially if you're failing. They went through what you are too, you know. Let them help you, they know more and can assist you when needed.
5. Be happy all around. Being depressed can make school seem a dreadful experience.
Now I don't find school enjoyable, but it doesn't waste my life.