Clap your hands!
More from Becky Bailey's child-rearing wisdom:
Principle: Focus on what you want, not what you don't want.
My middle child has a tendency to push his little brother around. I have told him not to do it until I am blue in the face and it has not had one iota of an effect.
Bailey would say I am focusing on what I don't want to happen - ie. the pushing. Her solution would be to say to him what I actually do want to happen.
So instead of: "Don't push him!" I have been saying: "When you push your brother he feels sad. You need to keep your hands next to your own body."
It has changed things for the better. And in the car it works a treat. We did a lot of "hands on your head", "Let's clap our hands together" and "You can touch your nose" on our hour-long trip to Sydney yesterday.
If you think about it, it makes sense from a lot of angles, but especially because the positive instructions are the last words that are implanted in their head. Instead of keeping an echo of "...push him" in their ears, they remember "...clap hands".