1. You can draw two points on your wrists at first, and then rotate around the back point. You don't need to draw points after you are proficient.

2. Put two wrists together, and the two points at the wrists are aligned.

3. The left hand is backward and the right hand is forward, so that the right hand is in front and the left hand is behind.

4. Turn your hand back and return to the original position.

Then the left hand is forward and the right hand is backward, so that the left hand is in front and the right hand is behind.

5. Re-rotate and return to the original position.

6, such a left and a right, can be repeated quickly.