Measure the flour and salt into a large mixing bowl. Add the shortening and cut it in using a pastry cutter or two knives, cutting together until the flour/shortening mixture resembles pea sized pieces
Mix in the water and stir with a fork, just until all the ingredients are clinging together. Do not over mix or the pastry will be tough.
Flour the top of your rolling surface and around the sides of your rolling pin. Draw together about 1/2 of the pastry mixture and liberally sprinkle with flour. Pat into a circle about an inch thick and then roll it out to about 1/4 of an inch thick.
At this stage, you can either cut the dough into circles to fit into tart tins or use this half of the recipe to fill the bottom of a 8 - 10 inch pie plate. If you are making tarts, you can probably re-roll the scraps one or two more times and then the remaining pastry will be too tough to work with. Repeat with the second half of the pastry.
Pastry needs to be baked at a high temperature (400 deg F) for at least 10 minutes for pies that are then reduced to about 350 deg F until the filling is cooked or for tarts you may continue to cook at 400 deg F for about another 5 minutes to cook the centre and finish the cooking of the pastry.