I picked up all the books off the boys' bedroom floor, pulled the few remaining ones out of the bookcase, boxed them up, and hid them in the attic. Then I threw away all the trash on the floor.
I was going to do the same thing for loose toys, but it turns out that they do not really have many toys up in their room. Good for them. I stuck the few odds and ends I did find in the chest of drawers they are supposed to keep treasures in.
This is not a punishment. I will retrieve some for them to read tonight, whichever ones they want, three or four per kid. We'll refill the bookcase slowly.
The room is bare. Picking it up tomorrow should be easy, a refresher course for all of us.
Back to basics.