Separate and joint accounts.
I can't abide the idea of someone being able to critise all my spending and like having the ability to buy things secretly (eg presents) and save for frivolous things eg clothes without it feeling like I have to explain it
However joint account is also massively helpful. My dB and dsil don't have joint accounts and were forever saying well I bought xyz, so can you buy the petrol?. I like the idea of when you do a joint activity you can both jointly pay or when you go food shopping the bill just comes out of the joint account
We have a discrepancy in earnings so both pay a percentage of our wage into the joint account. It does roughly work out as one pays bills, one pays rent etc.
I would say that at times we paid different percentages so it we didn't have wildly different amounts at the end in personal accounts eg. I didn't have 500 and she had 80 to spend.
I have seen people be strict with the percentages or insist on both paying the same amount and person A is left with barely enough money to replace broken shoes and person b is buying x boxes and nights out.
I'm fairly lucky in we both have similar spending habits
We will change when we have children as the wages won't allow for our current plan