Fit the decorating bag with tip 9 and fill 1/2 full with medium constistency icing. Hold the bag and tip at 90° angle to surface of your cake.
Squeeze the bag, applying steadily even pressure. As the icing begins to build up, raise the tip with it, but keep the tip buried in the icing.
Stop squeezing as you bring the end of the tip to the surface.
Lift the tip up and pull away from your piped ball. Use the edge of the tip to shave off any point so that your ball is nicely rounded.