In my case, both my wife and I are employed, most of our major debts are gone, and we have some disposable income. She has her hobbies, and I have mine. We don't get in each other's way.
All of that, plus we've always maintained separate bank accounts. I don't tell her what to do with her money, and she doesn't tell me what to do with mine. It won't work for everyone, but it sure works for us.