I used a very easy way to train hand commands. I would have the dog on a long check cord. I would set out dummies in 3 piles. Making a diamond around the dog with the dog in the middle. This of it like baseball. The dog would be the pitcher. I would have 1 pile of dummies on first base, another pile on second base, and the last pile on third base. With the dog sitting looking at you, I would give him a hand command to go fetch a dummy on 1st base( over is the command that I would use). He would go fetch the dummy and come back to the pitcher mound so to speak. I would make him come back and sit, then take the dummy from him. Then we went to second base, I would give him the back command, for hand command, I would put my hand directly over my head and tell him back. He would go and get the dummy and return and sit, I would take the dummy from him. This was a very easy way for my dogs to learn hand commands. Make sure that once the dog has a good idea of what he is doing, that you mix it up. Don’t always go in the same order or retrieves, mix it up. Make him do 1st base a few time in a row, and then go to 3 rd base. Once the dog has this mastered, then just do hand commands, no voice commands. Then you can do the same thing with the whistle.