Start in a wide lunge, with front leg bent at 90 degrees, and back knee just 1 inch off floor. With weights in hand, arms at sides, jump, lifting both feet off ground. Land softly, sinking deeper into lunge. Do 20 reps. Switch sides. Repeat.
Perfect your form: Avoid hunching upper body forward.
Dial it down: Ditch the weights.
Amp it up: Increase reps.