I've been teaching Joel to stay off people which is really hard for him lol, so what I've been doing is when new people come I keep giving him treats when he's being good and staying off.
Now what the little smarty pants does is go up to the person and sits for a few seconds and then he runs up to me to tell me he stayed off so he can get a treat, but hey at least he's staying off!

Can't believe how smart these guys can be