The first paycheck definitely helps ... but seeing how quickly it goes helps even more. We made him reimburse us for this uniform cost. He has to reserve 10% of his pay for tithe, 10% for short-term savings, 10% for our inconvenience (he doesn't drive yet), and 20% for long-term savings. The remainder, after taxes and his costs, is his to keep.
Also, after an 8-hour shift of standing on his feet, he is finally beginning to appreciate how his father feels after a hard day's work. Bliss!