Pulse the flour, salt and sugar in a food processor. Add about one-third of the butter; process until the butter is combined. Pulse in the remaining butter in 5 or 6 pulses to form coarse crumbs. Add the vinegar; pulse quickly a few times while adding 1/3 cup ice water. Squeeze some dough between your fingers. It should just hold its shape; if it's still crumbly, quickly pulse in more ice water by the tablespoonful. (Do not overwork the dough.)
Turn the dough out onto a large piece of plastic wrap. Wrap the dough, then press and flatten into a thin round. Refrigerate 1 hour.
Roll out the dough into an 11-to-12-inch round, about 1/8 inch thick, on a lightly floured surface. Center over a 9-inch pie plate. Fold in the edges and crimp as desired. Refrigerate at least 30 minutes before using.