Sift flour, salt and soda and sugar together in med. mixing bowl. Mix in shortening with tips of fingers; add buttemilk and gently knead into a semi-stiff ball of dough. (Note: Add more flour if needed.) Lift dough onto well-floured work surface, knead JUST UNTIL SMOOTH and firm enough to handle. Roll or pat (preferred) to 1/2" thick, and cut with floured cutter, or with knife, or rim of drinking glass. Place biscuits on greased cookie sheet, and bake in preheated 400 F. oven for 10 to 15 min., or until brown.