Whether decorating for a wedding reception, birthday party or just to liven up your home decor, create a colorful topiary ball for an out-of-the-ordinary look. The ancient art form of making topiaries dates back thousands of years and involves cutting or shaping flowers and plants into decorative shapes. To create a topiary ball, you need only a few basic floral supplies and flowers, making this an inexpensive, yet eye-catching craft. Select a floral foam ball that is approximately 6 to 8 inches in diameter. Using a craft knife, carve off a small piece of the foam ball so it will sit flat. Soak the foam ball in water for at least five minutes or until completely saturated. Set aside to let the excess water drain off, and then place it on a footed cake plate. Select about four dozen carnations to use for the topiary ball. Select all one color or use two different shades of the same color for a dramatic effect. Cut the flower stems to a length of 2 inches. Cut the stems at a 45-degree angle so they will absorb the water better from the foam ball, which helps the flowers to last longer. Insert the flower stems into the foam ball, starting at the top and working down around the ball to the bottom edge. Place the flowers close together so they completely cover the foam ball.