There are two things that you must do if you want to achieve a great crust. One is to add just enough ice water to you butter/flour mixture and the other is to make sure the butter doesn't get warm and you end up with a dough like chewing gum. By the way, this is where lard is superior to butter; it doesn't melt as quickly and gives you a flakier crust. I've found if you use a pastry blender to cut in your butter, keep everything cold, and put your flour/ shortening mixture in a food processor, and then, with the processor running, SLOWLY add ice water until the dough just starts to clump together, you're half way there. Remove the dough from your processor and place it on your work space and gently shape it into a ball. Flatten the ball into a disk ~ 6 inches in diameter, wrap it in plastic- wrap and place it in your fridge for ~ an hour. This fridge bit is to insure that the butter or lard doesn't melt and combine with the flour to make what I referred to as chewing gum. Okay, place your rolling pin in the freezer and when your dough is cold, roll it out to the proper diameter to overhang your pie dish ~ an inch. This is tough. One trick is to use flour as a lubricant. Keep your work surface lightly floured and when it's ready to place in the dish, flour the top surface, using a broad flat metal spatula, flip half of the circle of dough onto the other half to form a half moon shape. Place some flour on your work surface and, again with your spatula, slide it under the half moon so you can lift the dough off of the work surface and place it in your pie dish. Unfold the half moon and complete the shell.
If you screw up, as I still do sometimes, you can take the chewing gum and turn it into brioche. Depending on how much crust you're making, I add two eggs and some yeast to the chewing gum which makes it really moist and very difficult to work with. Using your hands or a wooden spatula you can mix the mass of dough to incorporate the yeast and eggs and then place the mess in the fridge to firm up so you can kneed it and form a brioche loaf. Place it in a loaf pan and let it rise to twice its volume and bake at 350 degrees for about 30 minutes. It really makes delicious brioche. Anyway, don't give up! You can do it. It just takes practice. Just don't let your shortening melt or handle the dough too much (which also makes the shortening melt).