Start with just the barbell and add weight as you progress. Now proceed as if you were completing a regular squat. Place your feet at shoulder-hip width, and perform a squat. When you reach the quarter squat position, explode and jump as high as you can. Place an emphasis on jumping straight up with as much power as possible. Display triple extension at the hips, knees and ankles. Do not waste movement. Perform 2-3 sets of 3-5 reps.