In an electric mixer (or in a bowl using a pastry blender), mix together 1-1/2 cup flour and salt then cut the butter in until crumbly. If there are chunks of butter, this is okay.
Gradually mix in the vinegar and water. Add more flour if necessary until a smooth elastic dough results.
Use immediately or refrigerate in an airtight container. This recipe also freezes well.
Notes
This recipe yields one single crust. If you are making two pies, be sure to double it. If you are making one pie that has a crust over the top, make 1-1/2 of this recipe.