Draw With Your Eyes Closed
You describe. They draw. Nobody looks.
One window, one pencil, twenty minutes of genuine quiet.
Sit them at a window and ask for an honest drawing of exactly what is out there. No imagination required, which is why it works.
Observational drawing is slow, focused looking, and it is one of the few activities that reliably settles a wound-up child without a screen. Removing the rubber matters, because it stops the loop of starting over and keeps them moving forward.
None needed.
Date the back of the drawing and keep it. The series is worth more than any single one.
You describe. They draw. Nobody looks.
Kitchen roll tubes taped to a wall, and a marble that keeps falling out.
A pine cone, some lard, and birdseed. Hang it up and wait.
Stand a toy in the sun and draw around its shadow.
A bucket of water, a decorating brush, and a whole wall to paint.
Old pans, a bucket of soil, some water, and no rules at all.