Sift the flour, sugar, and salt into a mixing bowl. Add the chilled butter and shortening. Working quickly and using your fingertips or a pastry blender, rub or cut the fat into the dry ingredients until the mixture resembles coarse meal.
Sprinkle on the ice water, 2 to 3 tablespoons at a time, and toss with a fork. Turn the dough out onto your work surface and, using the heel of your hand, smear the dough away from you, about ¼ cup at a time. Scrape it up into a ball and wrap in wax paper. Chill in the refrigerator for 2 hours.
Remove the dough from the refrigerator and roll it out to ¼-inch thickness on a floured work surface. For a single-crust pie, line a 9-inch pie plate with half of the dough and crimp the edges. Wrap the remaining dough and refrigerate or freeze it. For a double-crust pie, line a 9-inch pie plate with half of the dough and reserve the other half for the top of the pie.
To prebake, preheat the oven to 425°F.
Line the dough in the pie plate with aluminum foil and fill with beans or rice to weight it. Bake for 8 minutes, then remove the beans and lining. Prick the bottom of the dough with a fork and return the pie plate to the oven until the crust is golden brown, 10 to 13 minutes longer.