Learning basic sewing with a polystyrene plate, yarn, + plastic needle. I remember doing this with craft mesh when I was a kid and then graduating to sewing buttons by hand onto little pillows and pockets.
*I've dont this* Even without writing in chalk, water painting on the chalkboard is amazing (read: clean) painting the kids love! Write letters in chalk and have child trace over with water. Just like wet/dry/try from HWOT! So easy