Teach your dog to sit whenever you ask him to. Sit at the kerb when you cross the road. Sit in front of you. Then when he runs at you, or anyone else, if told sit he will sit.
BUT it has to be practised, and used constantly, not just now and then.
When he sits as you have asked reward him with a titbit...a very tiny one.
Sit while his food is being prepared.
Lying down is another skill that is useful. Lie down, I am busy. Lie down, I want to watch TV. Lie down, while we eat.
