Sift together salt and flour. Cut shortening into the dry mixture using a pastry cutter, until it is in pea size chunks. Then moisten with milk until you can form two balls. Roll out each ball till thin enough (one of them if you are planning on a top crust) and place in pie tins. Prick all over with a fork to prevent bubbles. Then prebake for ten minutes at 350 degrees. Fill pie with chosen filling, and, if desired, cover with second crust and prick holes. You can also put a shape cut out of the extra dough on top (brush it with beaten egg to make it turn golden brown).