The secret to flaky pie crust is not over-working the dry and wet ingredients.
In a medium size bowl, whisk together the flour and salt.
Add the butter, lightly toss with the flour and blend with finger tips into the flour.
Add the shortening, lightly toss with the flour and blend with finger tips into the flour.
Add about 1/3 the water, using a spatula, gently stir the ingredients. Add another 1/3 the water; gently stir.
Depending on the humidity of the day 3/4 cup flour might be enough.
At this point, the crust will have dry and wet spots.
Turn out onto a single layer of a Ziplock bag, gently press the crust together with the Ziplock bag until it is combined, still careful not to overwork. This technique prevent over-adding of flour which makes the crust tough.
Divide the crust into two parts. Lightly flatten each one into a disk. Wrap in plastic wrap. Chill for 1 hour and up to overnight.