Things You'll Need
Decorator tip #3 or #5
Have you ever wondered how bakeries are able to decorate those holiday cookies with so much detail? The trick is royal icing, a smooth icing that dries hard, making decorations long-lasting. To decorate cookies with royal icing, you'll need some basic cake decorating supplies.
Place a #3 or #5 decorator tip onto a decorating bag (or you may snip off the tip of a plastic sandwich bag).
Place several spoonfuls of royal icing into a decorator bag. Press it down to get out the air, and twist the top shut.
Gently squeeze out a teaspoon or so of icing to ensure air bubbles are out. Then outline the outer edges of the cookie and all the lines of the details without making any breaks in your lines for each section. Don't forget details such as eyes, buttons, feathers.
Remove all the extra icing from your bag, or set up another bag for the next decorating step.
Place several spoonfuls of icing in a bowl. Add 1 tsp. water at a time. Using a spoon, pick up a dollop of icing and drop it into the bowl, if the dollop disappears within 10 seconds then the icing is thin enough. Add food coloring for the fill color.
Reload your bag with the thinned out icing. You are now working with a liquid that will run out of the bag.
Start at one end of the cookie and work your way down, filling in the areas of the cookie in between the outlines. Work your bag back and forth to fill up that area. Don't do this step quickly, as the icing will soon spread. Give it time to do so before adding more icing.
Let the cookies dry at least 24 to 48 hours.
Once the icing is mixed, separate it into several bowls to create different colors. Color with a food coloring paste instead of liquid.
Royal icing dries quickly, so don't leave it exposed to the air; wrap unused icing with plastic wrap. If you are not going to work with it for a while, push the plastic wrap all the way down to touch the icing.