Make your pie crust, I NEVER buy crusts only make them, as store bought has hydrogenated oils YUCK! I only use Unsalted butter in my crusts. Line 9" pie plate your unbaked crust.
In a large bowl combine sugar, cornstarch & floor, mix well. Add berries and toss until completely covered with mixture, then squeeze a small amount of lemon juice over mixture keep mixing. Next dump mixture into unbaked pie shell. Dot with butter.
I love lattice topping, next cover fruit with lattice topping then with your CLEAN finger lightly wipe water over lattice topping then drizzle with granulated sugar. Bake in preheated oven at 400* for 40-50 minutes. I always bake my pies on the middle shelf. If your crust is getting to brown around the edges cover with aluminum foil until pie is just about done then remove foil to make sure the lattice gets nice and brown.
Remove from oven let cool to room temperate so the pie sets, you can always re heat individual pieces in microwave and top with fresh whipped cream OR Vanilla Ice Cream, YUMMY!