Using an icing bag, spreading icing with a spatula, and using rolled fondant are some common cake decorating techniques. Instructions for these and other cake decorating techniques are available on Wilton.com, Make-Fabulous-Cakes.com and Epicurious.com.
A basic step for cake decorating involves covering the whole cake in a smooth layer of icing. Start by placing a large amount of icing on the top of the cake, and then a metal spatula to spread the icing evenly over the top and side of the cake. Keep the spatula lowered to avoid picking up cake crumbs. Use a lazy Susan pedestal to make it easier to frost and decorate the cake.
To decorate a cake with an icing bag, spoon icing into a piping bag fitted with a metal tip. To create icing shapes such as petals or flowers, hold the piping bag upward at a 90-degree angle to the cake. To write messages on the cake in icing, hold the bag at a 45-degree angle.
Rolled fondant is a malleable cake topping used to form defined shapes or a smooth surface. To cover a cake in fondant, ice the full cake with butter-cream frosting, and then apply a sheet of fondant. Cut the excess fondant away from the edges of the cake.