The best way has always been to have excellent grades! Colleges will look at the GPA before anything else so the higher it is, the better. This is true for both admission and financial aid. Schools want the best students to attend their school so the GPA is a great way for them to screen for the high achievers. In addition, merit based scholarships are awarded based upon grades so a high GPA will also help you receive free money to pay for tuition.
Next, schools want a well-rounded student so this means having extra-curricular activities on your college application. So whether it be sports, organizations or clubs, volunteering, etc. make sure you participate in as many groups as you can.