To make Saturn or a comet, simply substitute those shapes. Draw a half-moon onto corrugated cardboard with a circle in the center the size of child's face; cut out with a utility knife.
Prime and paint cardboard with acrylic paint. Add dot stickers and glitter. Fold a 1-inch strip of felt around inner opening; glue. Trim outer edge with yellow masking tape. Punch holes on either side of opening just above child's ears; tie on elastic, adjusting to fit.