Combine flour and salt; cut in shortening with pastry blender until mixture resembles coarse meal. Stir with a fork, adding enough cold water, 1 tablespoon at a time, to moisten, shape dough into a ball, and chill.
Roll out dough to 1/3-inch thickness on a lightly floured surface. Place in a 9-inch pie plate; trim off excess pastry. Fold edges under, and flute.