The trick to good pastry shell is not to add too much water (which will make the dough tough) and not to overwork the dough. Following these two rules will allow you to produce flaky, buttery pie and tart shells. Extra dough can be frozen, either in batches or rolled out in shells. Wrap the dough well and it will last for a week or two in the freezer. Simply thaw the dough and roll it out as desired. Always use tart forms with removable bottoms.