Here is a different type of cookie icing, Cake_Princess uses it to frost her cookies. I got if from a post by Bunnywoman on the Wilton site. It is called Alice's Cookie Icing. You can thin it down with more water if you find it too thick to work with.
ALICE'S COOKIE ICING
1 lb sifted powdered sugar
3 TBSP. meringue powder
5-6 TBSP water
1/2 cup butter
The butter actually allows the royal icing to firm up to be stackable, but though it sets, it doesn't get hard.
Inserting the method I used - Squirrelly
Oh yes, and in case anyone else would like to know, the icing method...
Well, using the paddle attachment on low, cream your butter until well softened. Then sift your 1 pound, (4 cups if you are measuring by dry measure) of icing sugar. I sift before I measure it. Add the icing sugar to the butter, one cup at a time, beating on low after each addition. In a separate bowl, sift your meringue powder, to be safe. Then add the water it calls for - some folks like to add warm water instead of regular tap temperature. Whisk it well before adding it to the butter, icing sugar mixture.
Most people will tell you that because an icing has meringue powder in it, that darker colours won't bleed, but I don't find this to be true so if you are colouring the icing really dark red or blue or such, it will bleed out somewhat - moreso if the icing decorated cookies are stored in a cool place or frozen and then brought to room temperature, so keep that in mind when you choose colours. I found the icing tastes a bit like cream cheese icing. It works well and you can pipe with it. You may need to adjust by adding more or less water.
Incidentally, you don't have to follow this method, but I found that it worked best for me. The first time I made it I found that the meringue powder caused lumps if I just added it to the icing dry.