Take pretty much any important yet complex undertaking—like filing taxes, buying a house, or hosting a Super Bowl party—and a checklist makes it less daunting and more doable. There's no limit to the satisfaction of checking boxes off a list of tasks you've accomplished. Have we gone overboard in providing a checklist for missions ranging from packing for a picnic to hosting a Christmas cookie exchange? Perhaps, but since they're here, you might as well take advantage. And once you've completed an entire checklist, treat yourself to a cookie.