How about each agreeing to contribute to a joint checking account per month. Like $5K each per month to the joint account. For those of us who own our own business or are self-employed, my business account is mine, and my partner's business account is hers.
But after a few years of marriage we found it needlessly complicated and now we just have the operating account which we both can withdraw money from, along with various short and long term investment accounts which we both have to agree to pull money from. Perhaps it's because we've never really spent beyond our means that this hasn't caused any conflict in the past twenty years of marriage.