My partner and I have completely different spending habits and it's causing constant fights. What actually works?

Vague advice to "communicate" doesn't help because the real issue is usually that nobody's agreed on the actual rules, not that you're not talking enough. 1. Separate "our money" from "my money" explicitly. A shared account for joint expenses and separate discretionary money each of you can spend without asking permission takes a huge amount of friction out of day-to-day decisions. 2. Set a number, not a feeling, for what needs a conversation first — "anything over $200" is concrete; "anything big" means two different things to two different people. 3. Talk about what spending and saving each represent emotionally for each of you — often one person learned saving as safety and the other learned spending as freedom or care, and neither read is wrong, they're just different starting points. 4. Revisit the agreement periodically rather than treating it as settled forever — incomes, goals, and life stages change, and the rules should move with them. This stops being about who's "right" about money once there's an actual shared system — the fights were never really about the dollar amount, they were about not having agreed on the rules in the first place.