When we moved in together we opened a joint account in addition to our personal accounts and each paid 80% of Salary into that account, which then paid for all household costs including savings to a joint savings account.
When we bought our 1st house we pooled our individual savings and increased the contributions into the joint account to 90%.
When we married we moved to a single joint account.
We have always had individual accounts that we regard as joint, eg ISA's that have to be on one name, or for reasons of tax/account bonus etc and Credit Cards can only have a single primary cardholder who is actually responsible for the debt. These change over time.
This worked well for us, possibly because we both has similar levels of income and assets in the years before marriage and by the time children arrived and part time/sahm created a big income disparity we considered it all 'family' money. We've also been open and trusting in our communication, I can not understand situations where one partner does not even know how much the other partner earns. We also have generally compatible approaches to spending money, eg one of us is not spending a lot more than the other, although I sometimes wish I could spend a little more freely and now that my wife is a sahm I know she feels a little guilty about spending money on herself (which I tell her frequently not to feel guilty about).
one potential minor issue is difficulty purchasing surprise items for the other, but we have generally found ways round this.
If our relationship broke down in confrontational way then we could both cause issues for each other, we did not fully combine our finances until we had married so that we had some legal protection in any case.