Here's a little social story about "waiting":
I also have a "waiting chair" in my classroom (pic to be added later)! The chair has the wait picture taped to it and he must sit in the chair to wait, with a timer, for EVERY transition. In and out of work area, lunch, therapies, recess. It gets him used to the feeling of waiting and weans him off of constant adult attention.
So for a recap....
HOW TO TEACH WAITING
1. It's Time to Wait Social Story
2. Transition seat (waiting chair)
3. Wait card for sticky situations!
4. Quiet hands and WAIT before EVERYTHING