Parchment paper works for lining baking dishes or trays, wrapping fish or chicken for steaming inside the oven and as an alternative to using grease when baking meats. If you have a recipe that calls for parchment paper to line a baking dish but you don't have any, don't worry. Use an alternative and your dish should still come out well.
Aluminum foil can substitute for parchment paper in any situation. You can use it to line baking dishes or forms, to package meat and fish cooked en papillote -- in paper -- and even as a cone for doing fine icing and cake decorating work. Use it exactly as you would parchment, or follow the directions in your recipe that call for you to use parchment paper.
Waxed paper can also a substitute for parchment paper, although because of the wax, it can be a little stickier than aluminum foil. If you are using waxed paper in place of parchment paper to line a baking dish, spray a little cooking spray or rub some butter over the waxed paper before pouring in any batter or mix to keep it from sticking at the end of baking. Don't use waxed paper if it will not be completely covered by the batter.
Cooking Spray and Other Fats
If you prefer not to use wax paper or aluminum foil, cooking spray, butter, shortening or vegetable oil can be used in place of parchment paper in baking. Spray or lightly coat the baking surface completely, including the sides of the pan. If you are baking -- rather than roasting or using another technique -- you also can lightly flour the greased area. This will help prevent anything from sticking to the surface.