Cardboard crowns are a fun craft that can be created at a moment's notice. They can work as a part of children's make believe, as an easy prop for a play, or as a cute party favor. Cardboard crowns can be assembled using common crafts supplies, most of which you may already have, and require no more expertise than that possessed by the average child.
Use a tape measure to measure the head size of the person who will wear the crown. Measure the portion of the head just above the ears and eyebrows. If you don't have a tape measure, you can wrap a piece of newspaper around the person's head, then mark the length with a marker.
Trace an outline for the crown on a flat piece of cardboard. It should be equal to the length you just measured plus 1/4 inch. The top of the crown should be traced in a zigzag "V" pattern along its entire length. The bottom of the Vs should be at least 2 inches from the bottom of the crown itself.
Use scissors to cut the crown out, following the lines you have traced.
Wrap the crown in aluminum foil, taking care not to rip or tear the foil. Use glue to secure it in place if you wish.
Decorate the crown with additional embellishments. You can cut out pieces of colored construction paper to serve as jewels, put glitter across it to help it sparkle, color in your own decorations with a marker or cut out letters to spell words. Whatever you decide, secure the decorations to the crown with glue, then wait for the glue to dry before proceeding.
Bring the two ends of the crown together to form a circle. Staple them together. (This is where the extra 1/4 inch from Step 2 comes in; it holds the staples securely while still keeping the crown the proper size.) Staple the crown from the inside out and cover the inside staples with two small pieces of tape so they don't snag the wearer's hair.
If you don't want the person to know you're making a crown, measure the inside of a baseball cap or other kind of hat he wears. That should provide an accurate gauge.
Unless they're using safety scissors, children should let their parents do the cutting and stapling of the cardboard crown.