The way we work it is through a budget. We have a budget each month and have been doing so since 1989. I take all of our income each month (she works too), figure all expenses. We have a ledger book that this goes into, and everytime we buy something it gets accounted for in writing. In the budget, there are two columns, one for her and one for me. The agreement is that we can both spend our money for whatever we want. Now it is not a lot, so obviously, there are times that we either must save from month to month, or we talk it out between us. If we spend more than our alotted amount, we must pay it back (kinda like credit without interest) in the budget the next month. This works great for us, and for other things as well.