Mix and sift flour, salt, baking powder and sugar. Cut in shortening until mixture is as fine as cornmeal. Stir in the milk quickly. Turn out on floured board and knead a few times to make a smooth dough. Roll 1/2-inch thick. Cut in large rounds with biscuit cutter. Place half the rounds on baking sheet, spread with softened butter or margarine and cover with remaining rounds. Bake in hot oven (450 F.) about 10 minutes. Wash berries. Reserve 10 or 12 for garnishing. Hull remaining berries, crush and add sugar. Keep in warm place until shortcakes are ready. Lift tops from the biscuits, place bottom rounds on serving plates and cover with crushed fruit. Cover with remaining rounds. Garnish with whipped cream and whole berries. Yield: 6-8 servings.