01 - Whisk together flour, salt, and sugar in a large bowl until well combined.
02 - Cut cold butter into the flour mixture using a pastry cutter or fingertips until mixture resembles coarse crumbs with pea-sized butter pieces remaining.
03 - Gradually add ice water, mixing gently just until dough comes together. Divide dough in half and form into two discs. Wrap tightly and refrigerate for at least 1 hour.
04 - Roll out one disc on a lightly floured surface to fit a 9-inch pie plate. Press dough gently into the plate, trim edges evenly, and refrigerate while preparing the braid.
05 - Roll out the second disc to 1/4-inch thickness. Cut twelve long, even strips approximately 1/2-inch wide using a sharp knife or pastry wheel.
06 - Group strips into three sets of four. Pinch tops together. For each set, label strips left to right as 1-2-3-4. Cross strip 1 over 2, under 3, then over 4. Repeat with the new left-most strip until fully braided.
07 - Carefully transfer braids to the chilled pie edge, pressing gently to adhere. Trim excess dough. Use small amount of water to help seal if needed.
08 - Refrigerate the assembled pie for 15 minutes to firm the crust. Preheat oven to 400°F.
09 - Whisk egg with milk. Brush the braided crust evenly with the egg wash mixture.
10 - Line crust with parchment paper and fill with pie weights. Bake for 12-15 minutes until golden brown. Remove weights and continue baking if additional crispness is desired.
11 - Fill and complete baking according to your chosen pie filling recipe.