A poster for your door that lets your visitors know that your dog(s) are in training and asks them to look to you for instructions before entering.
I'm Not Sure I Like Your Tone
One of the most effective tools in keeping a dog on its best behavior is the human voice.
A Happy Dog Is A Well-Behaved Dog
Your dog will react to the way it is treated.
Dominance Theory: The Outdated Idea that Harms Our Dogs