My wife and I have moved all of our personal, individual spending to a dedicated card each. Sure, some stuff still makes it into other cards, but the simplicity makes budgeting so much easier. Even if we only accurate capture 90% of our spending, we close enough to targets that it doesn’t matter.

My general rule is a simple system that works well enough is better than a complex, but precise system.

We build our budget with this slop in mind, so anything left over is bonus.