This year I didn't make royal icing for the cookies, figuring we could extend the decorating by only fancying up a couple cookies at a time (only enough to eat that day). The trays get stacked up with the tub of sprinkles, tools, and plain baked sugar cookies when not in use.
This is ok, I guess. Not sure if it was less mess than using lots of bagged icing with not so coordinated hands, but it worked. We have had days of fun at least.