We have a joint account which we use for household bills, food, vehicle/house/garden expenses, petrol for both cars, joint savings and holidays. These are basically our essential costs for running and maintaining the household, vehicles and paying for holidays.
DH pays much more than I do into this as he earns twice as much as me, but that leaves us with about the same amount each month.
From what we each have left, we put some into personal savings, I cover costs for my DS (things like an allowance, bus fares for 6th form, clothes) and he covers costs for his dog (things like food, vet, kennels).
I have £250 a month left after that, and I think DH has something similar for personal spending.
Since the beginning of this year, I've been putting mine into a separate personal spending account so I can ensure I stick to a budget, as it's easy to dip into savings and I'm trying to avoid that going forward.
Mine is for clothes/shoes/bags, going out with friends, Christmas/birthday presents for friends/family, but also needs to cover things like new glasses, prescriptions, any toiletries bought outside weekly food shop. But I'm trying not to buy any more clothes/shoes/bags this year, let's see how that goes!
DH tends to spend his on CDs, new trainers every few months as he runs a lot and some beer (which doesn't come out of our weekly shop as I don't drink).
If we buy food out, that comes from personal spending, although DH doesn't really do that, but I do as I go out for coffees/meals with friends sometimes. We both mainly WFH so lunch at work is never an issue but when we go to the office we take packed lunches.
We both think it's fair and TBH either of us could save less one month or dip into savings if there was something we particularly wanted to buy. But we're trying not to since we're mid 50s and want to save as much as we can for retirement.