Look at That game. It's one of the most useful tools for helping a stressed dog calm down.
The Look at that game.
Start in the house. Have an object in your hand (book, plastic bottle) Wave it, say look at that, when the dog looks, say YES (or click) and give a treat. Hide it behind your back. Take a breath, and repeat. Put the object in different places, over your head, to your left, to your right, between your legs. Keep the game fun and happy.
The dog will learn to LOOK at something and then LOOK back at you for a reward.
The goal of the game is to teach the dog to look at a scary or overstimulating thing, now look at me.
Go very slowly. Look at one scary person, treat, go back inside where it's safe. Next time, look at two very scary people, treat, go back inside. If your dog spits out treats, you're too close to the scary thing. Back up.