1. Cut the margarine into the flour until crumbly.
2. Stir in water until dough sticks together.
3. Roll out on floured surface.
This is my great-grandmothers recipe for pie crust, used by everyone in my family. It originally called for hydrogenated vegetable shortening, but I replace it with non-hydrogenated vegan margarine and it works great. If you're not afraid of trans fat, you can go ahead and use the vegetable shortening instead of the vegan margarine, but I think it tastes better with the vegan margarine.
My favorite thing about this recipe is that I never have to write it down. The amount for each ingredient is just half of the amount of the ingredient before it. It is, without a doubt, the simplest recipe for pie crust I have ever encountered in my life, and it comes out perfect every time.