Lately we've been experimenting with an allowance for One, and I'm surprised to say it is working remarkably well. I've written before on how Two is generous with any money he has; One is less so, but the allowance is less to teach generosity and more to teach responsibility.
The rules (I designed this - of course there are rules) are as follows: $12 a week, divided up into three envelopes: one for charity, one for spend, and one for save. Of the charity money, I've asked him (but not demanded) that half go in the offering plate each Sunday; the rest he can save for any project he decides is important to him. Spending money is just that - spending money. He can't get far on $4 a week, and right now he is concentrating on saving each week until he has enough for a favorite book. Every two or three weeks he hands over his cash and I order his heart's desire on Amazon; he has me checking the UPS tracker online, and on delivery day he compulsively opens the front door to see if anything has arrived. No matter how many times I tell him the UPS man knocks, he can't help peeking. Finally, he has his "save" pile. The rules for that are - save for something big, not just books, and if you mess up and break something, your share of the damage comes out of your savings.
So far we've had a lot of success. He successfully saved for a old-fashioned Walkman, so he could listen to all his books on tape. He frequently puts all of his weekly charity money in the offering plate, and he's acquired four Redwall books "all on his own" with his spending money. I think (well, I hope) that he's learning how to use money constructively, set goals, and be patient. If he gets that, I couldn't possibly hope for more.