Pie is the classic comfort food dessert, but it doesn't make for pretty single-portion servings. If that's what you're looking for, your best bet is to scale down your plans and make individual mini tartlets, instead. The tiny shells make even a simple filling look pretty and elegant, and in a pinch you could give them a savory filling and serve them as appetizers. Most recipes call for you to prebake or "blind bake" the shells, so they're ready to fill and use. That step's not difficult, but you'll need a little bit of finesse to get the best results.
Choose the Right Dough
You might have to experiment a bit with your dough to get it right. A full-sized pie or tart gives you a little more leeway for the dough to not work perfectly, but in the tiny space of a tartlet pan, your margin for error is pretty small. You may find that your favorite pie crust recipe doesn't translate well to this smaller setting. As a rule, the best recipes for mini tartlet shells have a bit more fat relative to the amount of flour. That minimizes the effect of gluten, which can make your shells contract as they bake.
Take Time to Chill
One of the real issues you'll face with mini tartlet shells is that you really, really can't afford to have them shrink as they bake. With a full-sized pie, you can get away with that to a point, but mini tartlets are already so small you'll have no room left for filling. The secret to avoiding this is time and temperature. Once your pastry dough is made up and shaped to the pans, you need to let it chill for at least 30 minutes, and preferably longer. That makes time for the fat in your dough to harden up, so your crust holds its shape better in the oven, and it also lets the gluten in your dough relax so it's less likely to contract in the heat. Even better, make your shells ahead of time and freeze them, and then bake from frozen.
Apply Some Weight
Another problem with pre-baking your shells is that they tend to puff up in the middle, which also steals away the space you need for fillings. There are a lot of different ways to counter that, but filling the middle of your shells with some kind of weight is probably the most widely used method. First, you'll line your shells with parchment paper or aluminum foil, and press it carefully into each shell from edge to edge. For full-sized pies, bakers usually use beans or ceramic pie weights, but those are too big to work well with mini tartlets. You're better off to use smaller weights, which can get right into the corners of your shells. Rice works well, and so does plain sugar. The shells get partially baked with the weights in place, until the dough starts to set and firm up, then they're removed so the crust can crisp and become golden.
Choose a Different Technique
Weights aren't the only way to get a perfect tartlet shell, and some bakers just don't want to fuss around with putting weights in and taking weights out. One alternative is just to put a second pan on top of the shell you're baking. If you're using individual tartlet pans, for example, you can stack a second pan into the first one after the dough is in place. As they bake, the second pan shapes the dough and keeps it firmly in place. If you're baking your tartlets in muffin pans, stack a second identical or slightly smaller pan on top of the first to get the same effect.
Another option is to not weigh the shells at all. Just prick them thoroughly with a fork – professional bakers call this "docking" – and then push down any puffy areas with the back of a spoon partway through the baking time, before the dough has a chance to become crisp and brittle.
Take Your Temperature
Most recipes call for blind-baking shells at a relatively high temperature, usually 400 or 425 degrees Fahrenheit. After 15 or 20 minutes, you're supposed to take out the shells, remove the weights and parchment, and return the shells to the oven for another 15 or 20 minutes at 350 degrees. It works, but it takes extra effort, and that high initial heat is also going to increase the risk of your shells shrinking. It's better to bake your shells from start to finish at 350 degrees, or even a bit lower if your oven runs hot. They'll need 45 minutes to an hour to finish baking, but you won't have to take out your weights until they're done.
Take 'Em Out
Once the shells are baked, take them from the oven and move them to a wire cooling rack. Carefully lift out the weights off their sheets of foil or parchment, and set them aside. If you've stacked the pans instead, take off the top pan. Work carefully, because some of your shells might want to stick to the parchment or pan as you lift it off. If so, carefully coax it off and back into its own pan. Let the shells cool as directed in your recipe, then lift them out of the pan for filling and serving.