Cool the cake thoroughly before decorating. Remove crumbs and level the cake by placing the bottom layer on top. Insert strips of paper under the cake to prevent mess and remove before decorating. Spread icing smoothly over the cake layers and fill between layers to add height and flavor. Ice the cake on a platter before decorating to prevent accidents. Common decorations include icing, glazes, jellies, chocolates, sprinkles, fruits, nuts, and colored sugars.