Don't yell, don't whine, don't make faces, don't be passive aggressive, just take a deep breath when you're angry until you can talk calmly like adults. Then, make sure to talk calmly like adults. "IF YOU'RE MAD AT ME, JUST TALK TO ME." And make sure you do the same. If you're mad about something, don't tell about it. Talk about it. It has to be two way for this to work.

No one is perfect including you, so when your partner brings something up in a mature manner, try not to get defensive. Getting defensive basically guarantees fights.

Finally, choose your battles. Seriously. Again no one is perfect. Anytime you bring up something negative any time you criticize, it will hurt your partner to some extent. Most thing literally are not worth that.

We on a couple of occasions had a rule where we weren't allowed to say anything negative to the other for a month. Yes, we seriously did this.

We did not fight once that month. The problems don't go away but at least the fights do.

It is to me a TEMPORARY exercise worth trying because it helps drill into your head not to bring up petty shit, you then realize that brining up shit is what causes fights.

So if you bring something up to your spouse, I feel it needs to be something important enough to potentially fight over. If it's not worth fighting over, it's my opinion you should live with it rather than talk about it.

Maybe this is terrible advice I don't know. I'm sure it won't even work for many people. But to me it's the day to day sniping, dirty looks, dirty tones of voice, negativity, etc. that, to me, erodes love and breeds contempt. If you have an issue, either let it go, or if it's worth bringing up, bring it up in love in a calm manner, and be willing to hear your spouse's grievance without being overly defensive.

I really do think a temporary moratorium on expression of negativity CAN calm people down enough to get to the real issues.