Cut the butter into 1/2-inch cubes. Dump the flour, sugar, and salt into the bowl of a stand mixer fitted with the paddle attachment (or in a large bowl, if mixing the dough by hand). Mix for a second or two to blend the dry ingredients. Add the butter and then, running the mixer on low (or by hand with two knives or a pastry cutter), work the mixture until it's crumbly and the largest pieces of butter are no bigger than a pea (about 1/4 inch).
As the mixer turns on low sprinkle in cold water a tablespoon at a time. Try to sprinkle it evenly over the flour and butter. Continue mixing the dough as you slowly add water. The secret is to add just enough water until it just pulls together as a shaggy mass. If you add too much water it will cause the pastry to shrink into the pie pan and it won't look very pretty.
To roll out the dough for a double-crust pie -- Cut the dough in half and pat each piece into a thick flattened ball (see Shape and roll the dough). Lightly flour your work surface and tap one of the dough balls down with four or five taps of the rolling pan. Begin rolling from the center of your dough outward. Stop the pressure 1/4 inch from the edge of the dough. Lift the dough and turn by a quarter and repeat the rolling until the dough is at least 12 inches in diameter. Be sure to re-flour the work surface if your dough is sticking.
Using a pot lid or a circle of cardboard as a template, trim the dough to form a 12-inch round (this should give you a 11/2-inch margin all around your 9-inch pie pan). Fold the dough in half, slide the outspread fingers of both hands under the dough, and gently lift it and transfer it to the pie pan. Unfold and ease the dough round into the bottom of the pie pan without stretching it.
Roll out the other dough ball and cut a second 12-inch round to be used as the top crust.
The next secret is to freeze the completed shell completely before baking. This step also helps to minimize that shrinking pie shell effect.
Bake as directed for your pie recipe if using for a two crust pie.
If baking a pie shell for a premade pie filling:
Preheat your oven to 350°F When the pie crust is sufficiently chilled, line the pie crust with parchment paper, wax paper, or aluminum foil. Fill at least two-thirds full with pie weights - dry beans, rice, or stainless-steel pie weights.
Bake with weights for 20 minutes. Remove from oven, cool a few minutes and carefully remove pie weights. Poke small holes in the bottom of the pie crust with a fork and return to oven (without the weights) and cook for an additional 10 minutes, until the crust is golden.
Cool completely before filling. You may need to tent the edges of the pie with aluminum foil when you bake your pie, to keep the edges from getting too dried out and burnt.