If it's creamy frosting you like, here's the recipe to top off those sugar cookies. #3 in the top 10 cookie recipes for Chicago 2011 at AllRecipes.com.
In a large bowl, cream together the confectioners' sugar
and shortening until smooth. Gradually mix in the milk and vanilla
with an electric mixer until smooth and stiff, about 5 minutes.
Color with food coloring if desired.