Grease your pan with butter or shortening, then cut a circle of parchment to cover the bottom. Grease the top of the parchment, then sprinkle in some flour (or cocoa powder if you are making a chocolate cake) and roll it around to cover all of the greased areas. Bake your cakes and then run a knife around the outside edge. Your cake should pop out beautifully and you can then peel the parchment paper off the bottom.