Regardless of the costume you are ultimately creating, whether it be a balloon, a ball, a Christmas ornament or any other sphere-shaped object, the technique for creating the core shape of the costume is the same. With a few simple items found in your own home, you can assemble a bowl-shaped sphere that will serve as the centrepiece of your costume.
Instruct an assistant to hold a Hula Hoop suspended around your waist.
Measure a piece of fishing wire from the front right-hand side of the Hula Hoop, over your right shoulder, to the back left-hand side of the hoop. Cut the wire and tie one end to the front and one end to the back of the Hula Hoop.
Measure another piece of fishing wire from the front left-hand side of the Hula Hoop, over your left shoulder, to the back right-hand side of the hoop. Cut the wire and tie one end to the front and one end to the back of the Hula Hoop. The wires should crisscross over your shoulders and torso, holding the Hula Hoop in place around your hips.
Cut a hole large enough to fit your head through in the centre of a bedsheet. Do not make the hole much bigger than the circumference of your head because you do not want the sheet to fall below your shoulders. Choose a sheet colour that will coordinate with the rest of the costume. For example, if you are making a soccer ball, choose a white sheet.
Drape the sheet over you, poking your head through the hole. Cut holes where your shoulders are for your arms to poke through.
Cut away the strips and excess material on the sides, leaving just a long strip of fabric in the front and in the back. Knot these strips together between your legs and trim away any excess material, leaving the knot.
Decorate the bowl-shaped sphere as you see fit. For example, if you are creating a soccer ball, cut pieces of black felt and glue them to the sphere to replicate the look of a soccer ball.