I made a felt-board (also called a flannel board) for the twins when they were about 18 months old. It was really easy to hot glue some flannel fabric to a large picture frame and then cut out various shapes from craft felt for them to play with (the pieces stick on without glue and are reusable). I recently brought the felt board back out, and all three kids have been enjoyed it. Other than just being generally creative with it, I also made some Montessori-inspired sensory activities out of felt for them to work on...
