Making pastry once a year, like jogging once a month, will not result in any remarkable improvement and you likely will be discouraged if you can only recall one "less-than-flaky" attempt. First things first: Unless your environment is climate controlled, try to avoid pie making on a hot, humid day. If you work on such a day, then plan to refrigerate your dough at various intervals to retard the development of gluten. All ingredients should be as cold as possible. If you can remember ahead of time, refrigerate both the flour and measured water a few hours. Next, and most crucial, properly measure ingredients. This in itself is a debatable point. Ideally, ingredients should be weighed, as they are in a professional kitchen, because only weighing can account for accurate ingredient proportions. However, since most home cooks do not own a scale or have access to a reliable one, the best rule of thumb is to mix the flour with a fork or whisk slightly before using it. This is not the same as sifting (which would greatly alter the way flour is scooped and measured into a cup) but aerates the flour somewhat. Sifted flour will measures under (there is too little); flour that is scooped from the bag may measure over (there being too much).
Pastry is somewhat forgiving of measurement error, so if you see a mixture requires more or less ice water called for, you can adjust. And no one turns away the offer of homemade pie. But it will certainly help your search for the perfect crust if you start by measuring precisely. If you do become enamored with more advanced pastry making or intend to prepare large batches of dough, then purchase of a reliable scale. If you do switch to weighing instead of measuring remember that 4 1/2 ounces of flour is measured as "1 cup".
If you are making pie pastry by hand, start with chilled hands, then "cut" or "rub" the cold fat into the flour. What this odd and ubiquitous phrase means is to simply break up the fat into small pieces and toss them with flour. Use your fingertips to do this (your palms are too warm). What you want to have is a mixture composed of small bits or floured-coated "butter or fat crumbs". Don't worry about achieving that mythical state that cookbooks refer to as an "even, grainy mixture resembling cornmeal".
Evenly dispersed fat and flour results in a short crust that is somewhat cookie-like in texture. Uneven mixtures of fat and flour (some smaller pieces, some larger pieces), result in a long flaky dough. This latter type of dough looks slightly marbleized when you roll it out. This is fine. It is far better to err on the side of under-blending or cutting in the fat than overworking it. Above all, do not squeeze the flour-fat pieces together. Keep your touch gentle, almost reluctant, and the mixture dry.
This whole operation can be done in a food processor as well, but is somewhat harder to control. Also, inevitably, because the processor is so quick and capable, you do tend to wind up with a shorter (finer crumbs of fat) pie dough. It is only by working with your hands, especially as you are learning about pie making, that you can get a feel of the dough. However, if you are making lots and lots of pastry, there is really nothing wrong with resorting to your processor. If you happen to have a larger capacity processor, that's even better.
When properly made pie dough hits a hot oven, the moisture inherent in these butter or shortening crumbs explodes and turns to steam, causing the dough to be lifted into stratas of tender flakes. For this mini explosion to occur, the oven must be quite hot and the dough well-chilled.
Next, dissolve the sugar and salt into the ice water, then make a well in the center of the work bowl and stir in liquid. Unlike other methods that mix the sugar and salt with the flour, this method allows the grainy salt and sugar to be first dissolved with the liquid. Revolve the bowl as you work, combing through the dough with lightly spread fingers, bringing the mixture into the center to blend. When the dough congregates in the center and is a rough mass, turn it out onto a lightly floured pastry cloth.
Knead or work it very briefly then pat it all around to smooth it somewhat, folding it over (rather than kneading it) to refine this mass into a flattened disc. Wrap it in plastic and chill the dough (at least one hour, preferably several hours) before using. Fresh dough is too elastic to work with and must have a short relaxation spell before being rolled out.
To roll out dough, first dust your pastry cloth with all purpose flour. The recipe may call for dividing the dough into two slightly unequal halves. The smaller half will be for the top of a 2-crust pie. Place dough in the center and roll it from the center of the dough outward. Turn the dough clockwise slightly and roll outward again, eventually crating a circle. Use the same pressure over the whole surface of the dough and avoid rolling back and forth. Try to use only one stroke then turn the dough again. Lift the dough if it sticks and lightly dustit underneath with additional flour if needed.
When the dough is two inches wider than the perimeter of the pie plate you are using (one inch on each side), loosely fold into fourths and place the point of this triangle onto the pie plate and unfold it into place. Do not try and pick up the whole circle of dough to transport it. This may stretch the dough (as well as may result in a rip or tear) and this will cause it to "retract" in the baking or have a tough texture.
If at any point the dough retracts as you are rolling it, the gluten content has been provoked. The dough is indeed salvageable but you should place the dough in the fridge to relax it again. If you must use dough scraps, re-roll these only once as over rolled dough is tough and dry.