Swing Kicks

Balance on one leg and with a slight bend bring the other leg behind you and swing it up and back to the starting point. Do a bunch of reps while balancing on the standing leg, working balance, stability and a general warm up to all leg muscles. Slowly over time work toward a straighter leg and higher kicks with less movement on the torso/upper body. Keep a tight core and breathe out as you swing kick up.

You can add weights in you hands to increase the stability demand.