Cream butter. Add sifted flour and stir. Then add salt, powdered sugar, vanilla and chopped walnuts. Roll into teaspoon size balls and press down with fork making a criss-cross pattern on cookie. (Sometimes this is easier when you first dip the fork into a small amount of powdered sugar) Bake at 350 degrees until deliciously brown around edges. Approximately 10 to 12 minutes. Upon removing cookies from oven (while still warm), dip them into a bowl of powdered sugar until covered.