Is to have your own bank account.
Your husband will not understand that a bottle of foundation that you must by to aid you in keeping the "the we first met look" costs $24. Just like you don't understand why he spends $50 on some man thing that he seems to have 40 of.
Frankly, arguing with each other over personal items isn't worth it. Money is second to communication issues as to why couples argue and divorce. Often those two coincide with each other.
My mother in law (who has been married for 39 years) was the one who actually shared this secret to martial happiness with me. There should be an account for each other for your personal spending and then there should be a shared account for shared expenses like the mortgage/rent, utilities, groceries, kid activities etc.
Why should you have separate accounts? Its to keep your personal identity in a shared relationship. Neither of you will dictate each others personal spending which gives room for you to be you. When you first meet you like each other for the individuals that you are and make the choice to come together to compliment each other. I think often that aspect gets lost over time.
With having your own account you won't need to ask your husband if you can spend $100 on a new pair of shoes. You've saved your own money and can treat yourself to those new shoes. It works both ways too. Even if you are a stay at home mom/dad you should have your you money.
As someone who used to be in the financial world accepting responsibility for shared expenses of course should be top priority. You do need a place to live and food to eat. But you should be treated too and having the capability to spend your own money on small things you enjoy can be really empowering.
I know many at this time are struggling with income and expenses but even if you can cache away $5 here and there for yourself it can do wonders. Sell some of your kid's clothes at a consignment shop? Great! Turn that money into a little shopping trip to the thrift store and snatch up some "new to you" clothes. Or save it for a girl's night out with friends, you get the idea.
I think and have seen a lot of ladies and gents get "lost" in relationships that are dominated by money issues. That leads to arguments and resentment. Balance with financial matters are so important no matter how much money you have.