Everyone has their own way of doing things, but for me and my DH we both have personal current accounts where we receive our salaries. Then we have a joint account too, and we each pay in (by standing order) enough to cover all our regular household outgoings (mortgage, car, gas, electric, food, council tax, insurances etc) based on our individual earnings. All our bills get paid out of there. We review our household expenses together 2x per year, and adjust the amount up or down as needed. So for us, as DH earns (take home) about 2x what I do, he pays in say £500 and I pay £250.
We then also have a joint savings account which is there for emergencies and big purchases, and holidays. Again, we both save into that by SO in proportion to our earnings. After that we each pay from our own current accounts subscriptions for our own interests/hobbies ... eg he loves cycling and sport so he pays his own TV subscriptions for that and I pay for my own magazine subscriptions etc from mine. After that we each spend our own current account money as we see fit ... although to be fair he does seem to spend more on me (treats, clothes, etc) than I do on him, but he does have more left than I do.
When one of us gets a big windfall like a work bonus, or an inheritance (rare, but has happened) we sit down and discuss how much to put into our joint pot, and how much the person receiving it keeps for themselves. Usually we put 50% into joint stuff (like last year he got a good bonus so we bought a new sofa and carpet) and the other 50% he spent on what he wanted (for him a new mountain bike).
Might not work for everyone as our way does mean being very open about earnings and windfalls, but it works for us.
If you aren't married but are leading towards it, then I would definitely recommend being upfront about where your financial red lines are, and make sure you both know your respective financial situations from the off. Last thing you want to end up doing is paying off his old debts and resenting it.
Hope this helps. 