Styrofoam balls are commonly used as the core of Christmas tree ornaments. Covered in decorative fabric, these lightweight orbs can hang on trees or other delicate house fixtures without causing damage. The key to successfully covering a styrofoam ball with satin fabric lies in geometry -- a piece of fabric not carefully shaped to the contours of the ball will buckle rather than lie flat. But executed properly, decorating a styrofoam ball with smooth satin fabrics can yield an elegant homemade keepsake.

Wrap string around centre of ball. Holding string tight, draw a line on the ball using string as a guide. Rotate ball 60 degrees, and repeat. Rotate ball 60 more degrees, and repeat. The goal is to subdivide the ball into six equal segments.

Wrap parchment paper around half of styrofoam ball. Trace the lines of one segment, to yield an oblong, ovular stencil shape on the parchment paper.

Cut stencil out of parchment paper.

Lay satin fabric flat, and place parchment paper stencil flat over satin fabric. Using straightedge knife or rotary cutter, cut around stencil to cut out satin segment. Repeat for the five other segments.

Apply hot glue or superglue around the outside edges of satin fabric, and place fabric on ball, using lined segments as a guide. Repeat for the five other segments.