Pretty much always available to help.
I'm not sure what's making problems for KCZ, but it shouldn't be the pastry blender. Chill the shortening until it's cold enough to cut into small cubes with a knife. Put the cubes in a plastic bag and hold them frozen until ready to use.
When you cut them in, don't cut them in too small. Many recipes recommend that the flour/fat mix should look like "cornmeal" or "coarse cornmeal" after the fat is cut in, but that's much too fine. There will be a range of sizes, but if you want a flaky (as opposed to crumbly) crust, there should be a significant number of pieces of fat as large as baby peas -- at the smallest.
KCZ's problems probably come from too much water, although perhaps her fat is overheated from working. If you're worried about the fat getting too soft, you can and should rest the dry dough in the fridge.
You want to use as little water -- and ice water at that -- as necessary to bring the dough together. The less water, the flakier the crust. And, if it doesn't quite come together entirely, if there are a few unincorporated crumbs, that's okay. When you think the dough's come together enough, turn it out onto a sheet of plastic wrap and use the wrap to form a ball, then press it gently with your palm to form a disk -- extra crumbs and all. You should be able to see pieces of fat in the ball and disk.
Let it rest and autolyze in the fridge for at least half an hour before rolling it out. Don't hurry it.
Don't roll it too thin. Thin isn't more professional. Thin is tough.
Ultimately, what makes for "flakiness" are pieces of fat: neither too large nor too small; entirely coated with flour; stacked on top of each other (by hydrating the dough, mixing and forming into a mass); flattened by rolling; and melted during the baking process leaving stacks of very thin layers of pastry behind.
So, you need to make sure the pieces of fat are well coated with flour when cutting in, but not cut them too small. Use as little mixing (aka "work") and moisture as necessary to form a dough mass -- and no more. Roll only until you've flattened the pieces of fat, and reached an appropriate thickness (rolling is "work" too).
Remember: Work makes tough crusts. Wet dough makes for crumbly and/or tough crusts. The refrigerator and a little extra time are two very good friends.
There's no substitute for touch and learning to read the visual cues. This all becomes much easier with experience. Don't expect to be Jo-Mama, Master Baker the first few times.
Edited by boar_d_laze - 10/27/10 at 9:46am