In a medium bowl, cream the butter, sugar and salt.
Add the vanilla extract and continue beating until combined.
Add the flours and mix until combined. Gather the dough into a ball, flatten to a disk, and refrigerate until chilled – or for several days, if desired.
Preheat the oven to 350 degrees, lightly flour your work surface, and have baking sheets standing by.
Working with portions of the dough at a time, roll the dough to about 1/4 inch and cut with cookie cutters as desired. Right out of the refrigerator, this dough tends to be a little brittle and tends to crack apart, but as it warms slightly, it's easier to roll. If it does break apart, you can just gather up the pieces and mash them together.
Place the cookies on a cookie sheet. Parchment paper is fine, but you don't need a greased cookie sheet. You can re-roll the dough scraps and cut more cookies, but if the dough gets too soft, it can be hard to work with as it sticks to your work surface and flops about when you try to pick up a cookie. If that's the case, just refrigerate it for 10 minutes or so, to let it firm up, then continue rolling and cutting.
Bake the cookies at 350 degrees until lightly browned on the edges, about 14 minutes.
Let the cookies cool on the pan for a while before you transfer them to racks to cool completely. They're a little fragile when warm, but they'll firm up as the cool. These are still slightly delicate when completely cool, so don't plan on putting them in a box and shipping them across the country.