Working toward a purchase can build the anticipation of owning it at once, once and for all. Anticipating a needed purchase can soften the blow of having to come up with the money for a big ticket item without the dread of the debt and financing that come after. With some cash in hand for a down payment, even negotiating a lower total price is possible.
Bank accounts are fairly easy to open, and dedicating one to a planned purchase helps hold the money as it grows so it doesn't leak out through overall spending accounts. Watching a savings balance go up and celebrating steps toward a spending goal also creates incentives for avoiding small purchases along the way.
Researching options for buying used is another way to save and to know the track record or history of the item. Including the family in the build-up to buying a car or taking a vacation has lasting value in that your children will see a pattern of working toward something. Avoiding big spending sprees and using a layaway plan for school clothing, for instance, also adds excitement and a sense of the value of the goods.