The way that I think about cookies puts them in a few categories;
Drop
Bar
Rolled
Pressed
Refrigerated
Filled
Sandwich
Shortbread falls into the rolled category and offers an enormously flexible, reliable and excellent base recipe which can be used as a cookie, as a pie crust, as a tart foundation, as a base for a domed custard bomb, etc!
The sign of a great recipe for my 'Foundation Recipe' category is that it has near infinite possible flavor directions you can take.
Try this recipe, enjoy! Try it again with different spices, enjoy! Try it again..... well, you get the point.