I'd do it like this:

Mortgage and utilities split 65/35. All other bills (food, subscriptions, etc) split 50/50.

I'd say a marriage who keep their finances separate probably have bigger issues. The whole point of marriage is to become a union.

In that situation, sperate accounts won't fix overspending. All it would do is force one spouse cover for the other spouse's spending habits.

I don't know how that could be achieved without it being unfair to the one spouse who has to give up a higher percentage of their spending money.

If each spouse puts, say 90% of their income into a join account and the other 10% is theirs to spend as they will, what happens when one spouse makes a significant amount more than the other spouse? Can't see a marriage lasting too long in that situation.

A simple "let's discuss any purchases over 'x' amount" could solve that.

I just fail to see why someone would feel guilty about buying something (assuming finances are stable enough to support the purchase).

I find this advice counterintuitive to marriage. I feel finances should be combined as one. I know this is anecdotal but everytime I've heard about issues in a marriage that stems from finances, I find out that they treated their income as their own.