Fit the decorating bag with tip 1 and fill 1/2 full with thin consistency icing. Hold the bag and tip slightly at 90° angle, close to cake without scraping cake with tip and without flattening icing strings.
Beginning and ending at edges, pipe a continuous string of icing—curve it up, down and around until area is covered. Make certain strings never touch or cross. Don't leave any loose ends! Stop pressure, pull tip away.