Pour the flour into a mound on a countertop. Add salt and sugar; toss well. Work butter into flour with fingertips until it forms pea-sized lumps. Add the water, 2 tablespoons at a time, tossing with your fingers, until dough is crumbly and just starting to come together. You may not need all the water.
Form dough into a mound, then use the heel of your hand to push the dough away from you, flattening out lumps. Repeat. Shape into two equal disks, wrap in plastic, and refrigerate at least 1 hour.
Place one disk of dough on a floured pastry board; roll into a circle ⅛-inch thick. Fold dough gently into quarters and transfer to an ungreased 9-inch tart pan. Unfold and gently push dough into pan. Roll out second disk. Cut small decorative holes in center of dough, then transfer to flour-dusted cookie sheet. Refrigerate until needed.