We started with me handling all the macro-stuff (mortgages, loans, savings, investment, retirement, etc.) and my wife was suppose to handle the monthly stuff (utilities, cable, etc.) but she had a bad habit of just filing the bills and forgetting to pay them. So I took that shit over and got everything set to auto pay.
My wife also buys tons of little shit all the time. She also has to concept of cash flow, if she sees there is money in the account she thinks she is good to spend. I set everything up to automatically move the portion of the big expenses out of the checking account (savings, % of mortgage and car payments) when we get paid and back in when the payments are due to come out. Now any money she sees in checking truly is just spending cash more or less and I don't have to worry about her spending part of the mortgage payment on Jamberry's or tights or whatever stupid "come to my Facebook launch party!" shit she's gotten wrapped up in this week.