Sift the sugar and meringue powder together. Add water a Tablespoon at a time, and whisk well to remove the lumps. Icing should be almost the texture of pancake batter. ( don't use more than 5 tablespoons of water or it will be runny) do your best to whisk it all together well before each addition.
Separate Icing into 2-4 small bowls or containers ( it may see like a little but it goes a long way!) start off with a small drop of color and mix. Add as needed to reach desired color, but keep in mind the gels are highly pigmented, so less is more here. Note : Icing being used for outlines or writing, should be a thicker consistency than what you will "flood" or fill with, so take that into account.
Pipe a thin line around the edges of your cookie and let set for 5 minutes. Fill the inside, and use a skewer or toothpick to distribute icing evenly and eliminate bubbles, use a swirly motion and be sure not to get to close to the piped edge line. Let the cookie set completely then go back and pipe your phrases!
you can use wilton tip 2-4 for edging and writing, the smaller size is the thinner. if you have couplers, then you can make up multiple piping bags but if not, thats ok, what important is to have fun!