Pie Crust is one of those things that can make or break a dessert. It can also turn the otherwise enjoyable act of baking a pie from scratch into a somewhat daunting experience. It seems that avid bakers tend to be quite loyal to their technique, especially when it comes to the butter vs. shortening ratio.
All-shortening (a little lacking in flavor, in my opinion), Half butter and half shortening (good texture and more flavor than all-shortening), and all-butter (best flavor by far, and can still be as flaky and tender as the half and half version) are the main schools of thought when it comes to pastry dough. I am not a die hard loyal to one type or another, typically. I have used the butter/shortening combo for the last few years and have always been pleased with the results. Since I've been in Italy, however, I've been keeping to a strict all-butter pie crust regimen and I don't see myself going back anytime soon. Why the switch? Shortening wasn't available, so I used all butter out of necessity. It was a good problem to have. The flavor is much better with butter, and if you are careful with your technique the results will be just as flaky as with shortening. The biggest trick is not to overwork the dough and to make sure the butter is cold and stays in large lumps throughout the dough when you roll it out.
If you've ever made homemade croissants before, think of making all-butter pie crust in sort of the same way: The butter, when left in larger bits, provides the flakiness that the dough needs. The pie dough will have a buttery marbled appearance when rolled out. If you work the butter in completely, the dough will be more tough than tender.
I also find that my crusts have the best texture when I make them the old-fashioned way instead of using a food processor to pulse the mixture. It's easiest not to overmix when you're working it by hand. Feel free to do as you wish, but if you choose to do it by hand- you'll save a lot of dishes to wash and you'll probably have better results.