In the bowl of a food processor, pulse the flour and salt 5 or 6 times until well combined. (If a specific recipe calls for additional spices, herbs, cheese, vinegar, or lemon juice, this is the time to add them.)

Add the butter and pulse 10 or 12 more times until the mixture is crumbly and coarse, with various-size chunks of butter visible throughout.

Wedge 2 or 3 ice cubes, broken up if necessary, in the processor’s feed tube. With the machine running, pour up to ⅓ cup cold water over the ice in the ice-filled feed tube a tablespoon at a time, until the dough just comes together and begins to pull cleanly away from the sides of the bowl in jagged clumps. (Tip: Don’t let the machine run too long, and don’t worry if you don’t use all the water. Overworked dough and/or too much water are the main culprits in making pastry tough or dense. However, in warm weather or dry climates you may need up to 2 tablespoons more cold water.)

Move the dough to a lightly floured work surface and gently knead it 2 or 3 times. If it seems quite sticky or at all wet, sprinkle in another few teaspoons flour.

Give the dough a couple more quick, gentle kneads.

Divide the dough in half and shape into 2 discs about 5 inches in diameter and ¾ inch thick, or as indicated in the individual recipe.

Wrap in plastic and refrigerate at least 1 hour (or up to 2 days) to distribute the moisture evenly, or freeze for up to 1 month.