Kids hang their own coats with the help of stick-on hooks
My son is 3-1/2. We recently bought a new house and we managed to train him to take off his shoes and coat and put them in the coat closet. But his coat would just get left on the floor. Not really his fault since he can't reach the hanging bar.
My husband didn't want to put coat hooks in the foyer for fear that our main entrance would be a mess (he's one of those tidy husbands). So we went all winter picking up and hanging our son's coat ourselves.
Then the light bulb went off. I put one of those nifty, stick-on hooks on the inside of the closet door at my son's height and presto! He was hanging his own coat in the closet the next day!
I've shared my love of Command self-adhesive hooks and hangers before. You can use them all over the house (and I do, as detailed here). The best part is that you can remove them without damaging the wall or door finish.
As an aside: I find that preschool teachers are BRILLIANT sources of ideas for kid-friendly room design. My kids went to a home-based preschool and I was amazed by how much they could (and would) do themselves simply because everything was accessible and clearly marked.
Calling all fans of stick-on hooks: how do you use them in your house?
The comments of this post contain a bunch of good Command hook uses as well.