On a lightly dusted surface, roll out 1 pie dough disc to 1/2-inch thick. Place in a 9-inch pie plate with a 1/2-inch overhang and fill with your favorite filling. Roll together the remaining 2 pie dough discs into one 1/2-inch-thick crust and chill.
To make the ruffled bottom crust, use your fingers to pinch the overhanging dough by putting your thumb on the dough and pushing up on either side to pleat all the way around.
Remove the rolled crust from the refrigerator. To make the braided lattice, cut the crust with a pastry wheel or chef's knife into 15 strips 1/4-inch to 1/2-inch thick. Take 3 strips of the dough and braid them, pinching the top slightly to adhere the strips together. Use a chef's knife to trim the edges of each braid. Place on top of the pie from end to end. Repeat until you have 5 braids to cover the entire pie. Beat the egg and brush over the top of the pie.
After the pie is covered with the lattice design, roll out the remaining pie dough scraps to 1/4-inch-thick. Cut out 3 discs with a 1 1/2-to 2-inch round cutter. Overlap the 3 discs slightly end to end like a caterpillar, adhering them with egg wash. Roll them from one end like a cinnamon roll. Cut the roll in half to create 2 roses. Adhere to the top of the lattice pie with egg wash.
Bake according to recipe instructions for your pie filling and crust.