3 pastry bags; #2 and #3 small round tips; couplers and #65 and #66 leaf tips; squeeze bottle
Put about 1 cup of the royal icing into a small bowl. Add water, 1 teaspoon at a time, until it's the consistency of toothpaste. Add 1/4 cup of this icing to a pastry bag fitted with a number #3 pastry tip; this will be your outlining icing. Divide the remaining icing between two bowls and color each in desired color using food gel colors. Add each to a pastry bag fitted with a coupler and a leaf tip.
Thin the remaining 2 cups royal icing with water, 1 teaspoon at a time, until it's the consistency of shampoo or a very thick gravy. Put into a squeeze bottle.
Outline the cookies: Hold the piping bag with the outlining icing securely in your hand. Apply a little pressure to squeeze out the icing and touch it to the edge of the cookie where you want to outline. Gently but evenly begin to squeeze out the icing, keeping the tip about 1/2 inch above the cookie, using that slack to guide the icing as if it were a string. Make nice, straight lines, touching down the tip to anchor the icing at the comers, making your way around the cookie to outline it completely. Once all the cookies are outlined, let the icing set, up to 2 hours.
Flood the cookies: Holding the squeeze bottle very close to the surface of a cookie, squeeze out thick, squiggly lines across the surface of the cookie inside the outlined border to cover it almost completely. Use a toothpick to gently spread the icing and guide it to the edges of the border and to fill in any little holes, giving the cookie a gentle shake to settle the icing. The icing should be smooth and even across the surface of the cookie. Use the tip of a skewer to pop any bubbles at the surface. Repeat with the remaining cookies and let the icing set, about 30 minutes.
Use the colored icings with the leaf tip to pipe a decorative border around the edges of the set white icing. Place the tip just above the cookie surface and squeeze gently, slowly releasing pressure while you pull away to make a leaf shape.
Switch out leaf tips to #2 or #3 small round tips. Working with the same technique you used for the outline of the cookie, by anchoring the icing and then manipulating the "string" to make shapes, write the desired names onto the surface of the cookies. One easy and impressive lettering technique is the cursive print "Blend." Do a pretty, stylized capitalized first letter in the cursive style and then write the remaining letters in a lower-case print style. The first letter might be a little tricky, but you only have to worry about one! It adds drama, while the rest of the letters are very simple and easy to do.