To prepare a teena's overnight southern buttermilk biscuits recipe, first you need to prepare your ingredients. First, you'll need your flour, baking powder, sugar and salt. Then, add your milk and mix until combined. Next, mix in your dry ingredients until they're just combined, then add the wet ingredients to the dry mixture. Finally, knead the mixture until it comes together. You can use your hands to form the dough, or you can roll it out with your rolling pin. If you don't want to roll out your dough by hand, cover the bowl with plastic wrap and place it in the fridge overnight.