Wait for it ... "You always ...!" That's your cue. The natural response is, "No I don't," but a better answer is, "Okay, tell me more." Perhaps hard to do the first time, but it will open the door to information you don't have. Just being heard can reduce tension and keep things from escalating. That's huge. Remember, when they point something at you, ask for more information and make the effort to understand. Memorize it, "Okay, tell me more."
Say you're sorry and mean it. When you realize that you've contributed to your partner's distress, apologize sincerely. Whether it's leaving their brush where they couldn't find it or spending money without talking about it first, it was important enough to cause them distress. Understand and apologize genuinely. End it lovingly. The only noble purpose for fighting is fixing things in the relationship. Get it right, work it through to understanding, and reaffirm your commitment to one another. Appreciate how hard it is to get it right and thank each other sincerely for the effort it took.
Love isn't a state of perfect caring. It's an active noun like 'struggle', learning how the other thinks, keeping up with their changes and growth, understanding and appreciating the things they deal with in their own heart. It's a struggle that spans the years, and so worth the effort. You'll grow closer, but it's a choice, not magic.