Grab a medium size kettlebell, start by standing straight up with good posture (glutes and abs tight and shoulders back). Maintain this posture while lunging in reverse and passing the bell under the front leg and to the opposite hand. After passing the bell, step forward with the back leg until upright again. Now, repeat the same motion with the other leg while passing with the other hand. Remember always to maintain perfect posture throughout. Start with low reps(5 on each side) until you feel you can execute this movement flawlessly.
This drill is a great glute and hamstring developer. It also works balance, coordination, hip flexibility and adds a cool twist to the lunge exercise.