Combine flour and salt; cut in butter until crumbly. Gradually add ice water, tossing with a fork until dough holds together when pressed., Shape dough into a disk for a single-crust pie; for a double-crust pie, divide dough in 2 with 1 piece slightly larger than the other. Shape into 2 disks. Wrap and refrigerate 1 hour or overnight., On a lightly floured surface, roll 1 disk of dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. , For a single-crust pie: Trim crust to 1/2 in. beyond rim of plate; flute edge. Fill or bake according to recipe directions., For a double-crust pie: Add filling to pie. Roll remaining dough to a 1/8-in.-thick circle. Place over filling. Trim, seal and flute edge. Cut slits in top. Bake according to recipe directions.