First, preheat oven to 400 degrees.
Second, place the dry ingredients: self-rising flour and salt in a large bowl and make a well (or a hole) in the center of the flour in the bowl.
Third, pour the milk into the well in the middle of the flour mixture.
Next, place the vegetable shortening (or butter) in the well with the milk.
Then, using your hands, squish the vegetable shortening (or butter) and the milk together until combined. Some people use a pastry cutter, but I don't find it to be necessary. You can achieve the same effect with your fingers. It just gets a little bit messier.
Slowly mix in the flour by pulling it from the sides of the bowl.
When the flour is completely incorporated, separate the biscuit dough into 5 equal portions.
Roll dough into a ball. (The dough will be a bit sticky so you can just use a little flour on your hands to keep it from sticking) You could also use a biscuit cutter to make them a uniform shape and size. But I prefer to have the homemade rugged look.
Then, place the 5 biscuits into a greased cast iron skillet and pat down slightly.
Next, brush with melted butter.
Place the biscuits in the oven for 20 minutes.
Turn on broiler after the 20 minutes has passed and let the top of the biscuits get golden brown.
Finally, enjoy with your favorite toppings!