This is the foundation of a good high school record and will also endear you to your teachers. Participate in extracurricular activities.
Colleges look for well-rounded students who do more than just get good grades.
Do community service. This will make your application even more well-rounded. Colleges want to see that you won't shy away from academic challenges. Study for standardized tests long before you take them. The more you're prepared for the actual test, the better you'll do.