Add the water gradually—start with 1.5 tablespoons and mix well.
Check the consistency. If needed, add a tiny bit more water to thin or a bit more sugar to thicken.
Divide icing and add food coloring. (optional)
Decorate your cookies or cake and allow to dry.
Notes
Spoon the icing into a disposable piping bag for easy and clean decorating. Snip the end of the bag with scissors and decorate. Always start with a small hole. You can always make it larger.