If you are caught without any buttermilk you can make it easily by using 1 cup of skim milk and a tablespoon of any acid. Using white vinegar or lemon juice will work and these add more tartness. Using a tablespoon of cream of tartar will work as well and this will not be quite as acidic.
CAKE FLOUR- 2 Tablespoons conrstarch in measuring cup. Fill with unsifted all-purpose flour. Sift 3 times. 1 cup of this equals 1 cup of sifted cake flour.
BREAD FLOUR-Add one tablespoon of wheat gluten for every cup of white flour. Stir until the flour and gluten are thoroughly mixed and you have your own bread flour.
Making Baking Powder-Mix 2 parts cream of tartar with 1 part baking soda. For example, mix 2 tsp cream of tartar with 1 tsp baking soda. (Cream of tartar is used to increase the acidity of a mixture. So, you can't always use baking soda in recipes that call for baking powder. You can switch baking powder for baking soda, however, just expect the flavor to change a little. )
Eggs- (you may be out and still want to bake or cook, here are some good stand ins)