In advance: Prepare and roll out cookie dough. Cut using heart cutters. Bake and cool cookies. Decorate cookies with royal icing following imprinted designs. Outline cookies with tip 4 and sprinkle with pink sugar.
On double hearts design, pipe in center hearts with tip 4 and attach white heart sprinkles. On "Love" design, pipe tip 3 message. Place cookies on waxed paper-covered board dusted with cornstarch.
For Cupid, pipe tip 12 ball head; flatten with finger. Using tip 2, pipe dot nose and eyes; pipe outline mouth. Pipe tip 3 outline arms and tip 2 pull-out dot fingers and hair. Pipe tip 4 pull-out wings. Let dry several hours.
*Combine Christmas Red with Red-Red for red shown.