The bunny fist !!! OK just kidding but smiling makes you relax and for chicks makes them more attractive so why not ? Squat on your heels or flat on the feet as you wish and place your fists on the sides of the heels. Now either inhale or exhale as it is natural for you and bring your upper body over your shoulders as you let the arms bend a little as springs to make the mass into elastic power. now bring your legs back and place them as far as it is comfortable and let the hip recoil to over the heels and bring the upper body after it and again place the fists at the side of the heels. Do that a few times (10 is for little girls and 1,000,000 is for people who have a too much free time) and reverse the order. The intent of this exercise which makes it more than just moving is the placement of the body parts in an angle or straight under or over another body part. This is a very easy way to alighn yourself and can be used to create a spring or whip motion (I like the whip analogy better) by cascading the change here and there.