Avoid kneading the dough too much when making your pie crust. Handle the dough just enough to mix it and roll it—not a touch more.
Pie doughs are sensitive. Try not to pull or tug the dough when fitting it in the pan—it can cause it to shrink when baking.
Peek On Your Pie
About halfway through baking, check on the pie—you might need to cover it with foil to prevent over-browning.