Roll one pie crust out to fit your pie plate. Place the crust in the pie, letting the edges overhang. Chill 30 minutes. Roll the second pie crust out to fit the pie plate and chill while you prepare the filling.
Fill pie as desired using your recipe.
Remove rolled out crust from the refrigerator. Using a knife, pizza cutter, or pastry wheel, cut strips in the pie crust that are 1/2-inch to 1-inch thick. Use a ruler to help keep them straight, if needed.
Pick up strips of the pie crust and lay them over the pie with gaps between that are the same width as the strips. Try to use the size strip that matches with the location on the pie (smaller strips close to the sides, longer strips in the middle).
Fold over alternating strips and place a new strip perpendicular to the ones you already placed on the pie. Unfold the strips, then repeat using the alternating strips. Continue the basket weave until the pie is covered with the lattice.
Brush the lattice crust with a bit of egg wash (just beat an egg with a fork like you're making a scrambled egg and use a pastry brush or your fingers to lightly brush it over the crust). This is for browning. Sprinkle with coarse sugar, if desired.
Trim edges and crimp as desired. Chill pie for 20-30 minutes, then bake according to recipe directions.