Mix butter, shortening, flour and salt together in a food processor or using a bowl and a pastry cutter. Mixture will be dry with various size clumps of butter and shortening throughout. Slowly add the water 1 tablespoon at a time, mixing the dry ingredients to coat. Continue to add water until dry ingredients start to stick together and the texture of dough forms.
Lay a piece of plastic wrap out on a work surface and place the pie dough on top of it. Lightly knead the dough together just for a minute and shape it into a disk. Wrap the dough and place it in the refrigerator to chill for at least 30 minutes, or up to 24 hours. Pie dough can stay in the refrigerator for up to 1 week.
When ready to use simply unwrap the pie dough and roll it out on a floured work surface. Carefully transfer the pie dough to the pie dish, gently pressing it into the dish to cover the bottom and sides. Trim and shape the crust as desired. Follow instructions of the pie recipe you're making!