Whisk together the flour and the salt.
Add shortening. Use a fork or pastry dough blender to mix until crumbly.
Then add the butter. and work together until roughly crumbly. Be careful not to overwork the mixture. It should not be smooth at this point.
Mix the vinegar with 2 Tbsp water and toss lightly to combine. Add more water, a little at a time, to make a dry, chunky mixture.
Shape dough into a ball, flatten to about an inch thick. Cover and put in refrigerator for 30 minutes.
Remove from the refrigerator. Roll out into a circle of the size needed. For a 9 inch pie, your circle will be about 12 inches in diameter.
Add filling, if it is ready. Or put in the refrigerator until ready to fill.
Or, if your recipe calls for a pre-baked crust, bake according to directions.