Cold butter. For flaky piecrust, it’s important to start with very cold butter, so that it doesn’t melt while you work it into the flour. When this happens, butter becomes too thoroughly mixed with the flour, resulting in a mealy, crumbly crust rather than a flaky one. Freeze butter briefly if you have warm hands, live in a warm climate, or are making a very large batch of pie dough. It’s also a good idea to chill the bowl and even the flour when making pie in warm weather.
Just enough water. For a tender piecrust, don’t add too much water. Water contributes to the development of gluten proteins. If you add more than necessary, the resulting crust may still be flaky, but it will be tough rather than tender. For these reasons, trust your fingertips over your eyes: The dough should hold together when pressed between your fingers, although it will still look pretty shaggy.
Easy rolling. Take the time before chilling the dough to form an even, circular disk with clean, smooth edges. This will make rolling out the dough much easier because the edges are less likely to crack.
Crisp crust. Bake filled pies on a preheated, rimmed baking sheet and use a lightweight metal pie dish. Both will help set the crust quickly, preventing it from getting soggy. Baking on a sheet is also handy for catching bubbling juices.
Put the flour, sugar, and salt in a medium bowl and stir with a rubber spatula or a fork to combine. Add the butter to the bowl. Rub the cold chunks of butter between your fingertips, smearing the butter into the flour to create small (roughly 1/4-inch) flakes of fat.