Using a food processor combine flour and salt, add in butter and pulse until it resembles coarse crumbs (pea size). If mixing by hand, use a pastry cutter to cut butter into the dry ingredients.
Add ice water with food processor running until the dough begins to hold together but is not wet.
You should be able to squeeze the dough gently into a ball without it crumbling apart (if you are not able to, add in additional ice water 1 tsp at a time)...do not overmix or your crust will not be flaky but will turn out heavy instead!
Divide dough in half, shape into discs on plastic wrap. Wrap and place in fridge for at least 1 hour (or freeze up to 1 month if using later).
When ready to use, roll dough on floured surface with a marble rolling pin. You can roll back over the pin to place over your pie dish, or use my fun trick (see site!).