Make your command words have meaning. Dogs have the ability to learn a lot of language. It is important to know that when you begin your obedience program you save certain command words to be used only when the dog is on leash and when you are planning on backing up the command should it fail. The reason being is that you want these words to have a lot of meaning to your dog. If you tell your dog to come while they are off-leash somewhere (before they have been off-leash trained) and they do not come you have just destroyed the meaning of that word to your dog.