Start with one foot flat on the ground and the other foot tilted up on the ball of the foot. All of your weight should be on the ball of that foot.
Using your body weight on the tilted foot, press it down and slide it back. This should be done in one motion. Your tilted foot is now flat at this point. You should keep your back straight.
Lift your other foot as the tilted first foot goes flat. The stance will be the same for this foot as it was for the first foot in Step 1. The weight will be on your new tilted foot. Remember to keep your back straight.
Repeat step 2, like you did with your first foot. Remember that the movement should be smooth and fluid. Take a moment to practice the form on each foot before continuing. Your back should be straight during the practice runs.
Perform the motion on each foot, tilting and sliding. Start with your right foot first, then your left, then right again. Continue alternating feet, leaving only one second between your motions. All of your weight should be on the tilted foot only. This is the key to mastering the smooth moonwalk.