Whisk together dry ingredients. (If you'd like to add dill, sage or any other herb or flavoring, now is the time to do it.)
Using a pastry cutter, cut the cold butter into the dry ingredients. Make sure it is well incorporated but still a crumbly mixture.
Add buttermilk. Stir into the dry ingredients being careful not to beat the dough or over mix it.
Turn dough out onto a well-floured cutting board and move it around to make it into a very soft, pliable dough. You may knead it only 4-6 times. Remember, don't overwork the dough.
Pat out to 1" thick and cut out biscuits with a 2 1/2 inch cutter. Place on cookie sheet. (You don't need to grease the cookie sheet, but I did spray mine with butter flavored cooking spray.) Brush milk lightly over top of biscuits.