Sift the flour, the salt, and the sugar together.
Cut in the shortening with a knife or a pastry cutter.
Then mix in the cold water a tablespoon at a time, until the dough holds together but is not sticky. (Should you add too much, shake in a little flour to dry out the dough.) Chill the dough.
When working with the dough, handle it as little and as lightly as possible. Cut the dough in half. Place one half on a pastry cloth or on a floured board. Roll it with a rolling pin to a thickness of one-eighth inch; do not stretch it.
Cut the crust 1 inch larger than the piepan. Folding it carefully in half, lay the fold across the center of the pan, unfold it, and shape it to the pan.
If you have a top crust, repeat the cutting and folding operations. Lay the crust on the pie, trim it, moisten the edges with water, and press it closed with a fork. Poke holes in the top.
You can store leftover dough for several weeks in the refrigerator, wrapped in waxed paper.