Set realistic expectations. These expectations might cover areas such as getting homework done every night, behaving well in the classroom, getting a good grade on a certain project or test, and so on. These expectations are important motivations, so make them specific and achievable, but don't be afraid to set the bar high. People achieve according to the expectations set for them.
Reinforce good habits with rewards. When a student performs well on a test or has exhibited good behavior over a certain period of time, reward her: give her an extra 15 minutes of television time, take her out to her favorite restaurant or come up with another treat. Students who have performed well and worked hard deserve a little recognition; this reinforces good habits and makes them more likely to occur again.
Spend time studying with your student. Set aside some time each night to help him with his homework. This shows him that schoolwork is important and that he is important too. This is also a great time to talk with your child about the material he is working on, reinforcing the concepts and helping him make real-world connections to what he is studying.
Model positive attitudes and behaviors toward school. You won't always agree with the teacher or with some of the work your child has to do, but if you act like it is stupid or not important, your child will think the same thing and will believe it is okay to not care about their schoolwork. Once they witness negative behavior from you, it is very hard to reverse this impression.