On the Internet you can find a variety of programs for the family budget, they will help you keep taking it into account, recording all income and expenses. When you start doing it, carefully noting the program every purchase, you will be very surprised at how much spending money on all the small stuff, without which it could well do without.
Having started to keep records, identify with her husband, the amount that must be allocated monthly to mandatory spending: food, utilities, hygiene items. Mortgage spending this amount for contingencies. All other purchases, beyond the approved list, discuss together. Each of you should refer to the proposal to discuss money matters without aggression, and not perceive it as a waste of charge.
Try to spend the equivalent of an additional allocations from the family budget, optimal: the same thing the same quality you can not buy in the boutique, and in the usual mall, and it will cost you much less. Do not hesitate to slow down each other in order to avoid unnecessary spending, learn pragmatic approach to money.
But do not put the blame occasional extravagance, accusing the wife that it makes it impossible to buy a vacation or a trip to another more right purchase. Nothing terrible happened, and that's no reason to pick a quarrel, the more that he already knew it all. In a pinch, you can calmly explain that overpayments could have been avoided, waiting for the nearest sales or make a purchase at another store.
The best proof of correctness of the chosen approach to money matters, will no scandals and accumulated after some time, the amount of money you can spend on a family trip or a major acquisition.