Before you put the pie filling in, put a thin layer of cornflower in, it will soak up the juices and stop the pastry from going soggy. Never failed for me.
Use a metal tin, partially blind bake the base before adding the filling and lid, have your pie filling quite dry and have extra gravy or fruit juice to warm and add on serving. Have the oven up to temp before putting the pastry in.
daisy Ido not fancy your pies with CORNFLOWER try usi ng cornflour instead!' Joking aside I always heat a heavy metal baking sheet and place your pie on that.