Gather a square piece of paper
Fold the paper diagonally both ways
Cut along each diagonal fold from each corner toward the center, stopping before the middle
Punch a hole in the center and in every other cut corner
Bring one punched corner to the center
Insert a pin or brad through the corner and center holes
Repeat with the remaining punched corners, alternating them toward the center
Secure the pin or brad to a pencil, straw, or stick
Leave enough space for the pinwheel to spin freely