A pillowcase, a large piece of fabric, a scarf, or an adult-sized skirt make an excellent child's cape. Use a bulldog clip or clothespin to hold the front of the cape together.
Crowns are easy to make out of colored paper.
Cut the paper into a length to fit a child's head, with several points on the top. Supply your child with plenty of crayons, markers, cotton balls, glitter, glue, used aluminum foil, felt, ribbons, and anything else that can transform a ring of paper into head gear fit for royalty. Finally, make a wand. Cut a ten-inch square of colorful wrapping paper. Then, along one edge, cut every quarter inch or so.