Combine flour, sugar and salt. I use a food processor, feel free to do this by hand, using a large bowl and a whisk.  (this is also where I would add any herbs or spices to a specialty pie crust)

Add the cubed butter and shortening and pulse only until blended to a rough, crumbly texture. It should only take 2 or 3 pulses. You still want to see large pieces of butter (the size of marbles). Or use a pastry blender or knife to achieve this.  Try not to overwork with your hands though- their warmth will warm up the butter too much.

Whisk the egg, lemon juice and 2 tbsp of the ice water in a small bowl.

Add to flour mixture and pulse just till the dough comes together into a rough ball. Don't worry about grabbing every little bit from the sides, you can add this to the ball you turn out onto the counter by hand.  Ideally you should still see pieces of butter.  If it isn't coming together in the first few pulses, add more ice water, but no more than the original 1/4 cup stated in the ingredients.  On a humid day you will most likely need less water.

Shape the ball into two disks and wrap. Chill at least 1 hour, or freeze till needed. If using these disks for uncovered pies, then you can divide them into equal sized disks

Take out one disk and let return to room temperature for 10 minutes. . Don't roll a disk that is still cool, it will crack along the edges. Place it on a well floured counter.Flouring your rolling pin, roll the disk out. Decrease pressure as you reach the edges. After each roll, spin the dough 1/4 turn. Keep flouring all the surfaces to keep from sticking. Roll to 2-3 inches larger than the pie plate you are using (should be around 1/8" thick.)

Either roll the disk up around the rolling pin and release it over the pie plate; or dust with flour and fold it in half and then in half again loosely and lay across the pie plate and then open it up. (In either case make sure that the dough is floured enough so that it won't stick together)

Allow the pastry to fall down the sides of the pie plate, so that there are no gaps between the dough and the pie plate. This will ensure that the dough will not pull up from the base, or shrink during baking. Trim it, allowing enough of an edge to work with the type of crimp you wish to use.

Place the prepared pie shell back into the fridge to chill for about 20 minutes.

From this point follow the directions for the pie recipe you are using.

Repeat the above instructions for the remaining disk of dough. If using as a lid for a covered pie, roll to about 2 inches larger than the pie plate, allowing it to cover any raised filling. 

Or use to create lattice or cut outs (either with a well floured cookie cutter or free hand)  Cut out the dough on a parchment lined sheet, but don't remove transfer the entire sheet over to a baking sheet to cool in the fridge.

Place the baking sheet in the fridge for 15 or so minutes.  Once they come back out, let them soften just a little so that they don't crack or break when you start using them.  If they warm up to much as you work with them, return to the fridge for a few minutes.

Use an offset spatula to remove the piece you are working with. Dab the place on the pie where you want to place the cut out with a little water to help adhere the dough.

Once your pie has been filled and covered the way you like, place the finished pie back in the fridge for at least 15 minutes. Once the oven is warmed up, only then take the pie out and do an egg wash. The fridge time will help the pastry from shrinking too quickly when it goes into the oven.

See blog post for more details