Combine the flour, salt, and sugar in the container of a food processor; pulse once or twice. Add the butter and turn on the machine; process until the butter and flour are blended and the mixture looks like cornmeal, about 10 seconds.
Place the mixture in a bowl and sprinkle 3 tablespoons of water over it. Use a wooden spoon or a rubber spatula to gradually gather the mixture into a ball; if the mixture seems dry, add another ½ tablespoon ice water. When you can make the mixture into a ball with your hands, do so. Wrap in plastic wrap, flatten into a small disk, and freeze the dough for 10 minutes (or refrigerate for 30 minutes); this will ease rolling. (You can also refrigerate the dough for a day or two, or freeze it almost indefinitely.).
You can roll the dough between two sheets of plastic wrap, usually quite successfully; sprinkle both sides of it with a little more flour, then proceed. Or sprinkle a countertop or large board with flour. Unwrap the dough and place it on the work surface; sprinkle its top with flour. If the dough is hard, let it rest for a few minutes; it should give a little when you press your fingers into it.
Roll with light pressure, from the center out. (If the dough seems very sticky at first, add flour liberally; but if it becomes sticky only after you roll it for a few minutes, return it to the refrigerator for 10 minutes before proceeding.) Continue to roll, adding small amounts of flour as necessary, rotating the dough occasionally, and turning it over once or twice during the process. (Use ragged edges of dough to repair any tears, adding a drop of water while you press the patch into place.) When the dough is about 10 inches in diameter (it will be less than ¼-inch thick), place your pie plate upside down over it to check the size.
Move the dough into the pie plate by draping it over the rolling pin or by folding it into quarters, then moving it into the plate and unfolding it. When the dough is in the plate, press it firmly into the bottom, sides, and junction of bottom and sides. Trim the excess dough to about ½ inch all around, then tuck it under itself around the edge of the plate. Decorate the edges with a fork or your fingers. Freeze the dough for 10 minutes (or refrigerate it for 30 minutes).
When you’re ready to bake, prick it all over with a fork.