In the bowl of a stand mixer (or using an electric mixer) combine sugar and ¼ cup milk. Mix until smooth. Add milk as need to create a smooth mixture, one tablespoon at a time. Add corn syrup and almond extract.
To decorate cookies, your outline icing should be the consistency of toothpaste, your flood icing should be the consistency of corn syrup.
Add food coloring one drop at a time until desired color is reached. Pour into bottles, decorator bags or a cup. Keep unused icing sealed until ready to use.