Zen hand is a fabulous exercise to start teaching your dog self control. If you work through it systematically you can also teach your dog the concept of staying still in the presence of fast movement, which is something a lot of dogs struggle with in any exercise.
There is also a video version of this tutorial available to see at: https://www.youtube.com/watch?v=usHeLQwOItE
Give this exercise a try and let us know what you think! Hard? Easy? Helpful? If you’re having any problems we’re happy to help coach people in the comments.