Use a paper towel to spread shortening or unsalted butter on the inside surface of the baking pan, lightly coating the bottom and sides of pan. Avoid using salted butter as it can cause sticking when baking at temperatures over 400°F.
Spoon a small amount of flour into the greased pan. Then, tap and rotate the pan until the entire greased surface is coated with flour. Invert the pan and tap out any excess flour before filling with the prepared batter.