HI:"Working in the summers can help a lot."
Start from an early age with the understanding that you and they will participate financially in their further/future education/training.
The sooner they start owning their future(financially and intellectually)the less likely they are to "bomb out" along the way.
Now you might say that is part of growing up but why not start the grow up process early?
The difference is a beer VS a case of beer!!