A couple of things that help us are 1) focusing on what we're doing right-the ways we've handled things that have left us feeling good about both the resolution we arrived at and our relationship with our kids and 2) me telling dh when he's handled something in a way I admire or vice versa 3) asking each other for opinions and advice when we're struggling (we are partners working together after all, and the only other person who knows our kids as well as I do is dh).
We do still talk about what either or both of us have done that isn't working or that one or both of us is uncomfortable with, but not every single time-only when it's an ongoing thing or a particularly bad day (or in some other way a "biggie"). But when we're focusing more on what "works", and only just noticing what hasn't worked and learning from it rather than dwelling on it, we do better as parents and as partners. "What you focus on you get more of."-I don't remember which parenting book that comes from, but I think it applies to everyone.
Sometimes when we're in the midst of a conflict and I disagree with the way dh is handling things I might not say anything (because it's not
a huge deal, just my preference even if I don't want to admit that, and he's responsible for his own relationship with his kids-I don't want to and I shouldn't be telling him how to interact with our kids all the time), I might wait until things calm down before I talk to dh, or I might make a suggestion ("maybe we
should just..." or "maybe she needs..."), or I may just find a way to lighten the moment with some humor. Depends on the situation. He has the same approach when he disagrees with me. And sometimes one of us does say something by way of suggetion that makes the other defensive. That kind of thing just happens sometimes.
Forgiving myself is much the same. Dwelling on what I've done wrong and getting stuck in the guilt actually prevents me from growing and learning and progressing in the way that I want. It's better, for me, to simply notice that I've done something wrong, to accept it, to learn from it, to apologize to my child when necessary, and to move on to the next moment.
ETA: For getting through those tough moments and for moving on from them, I have found that a sense of humor is totally essential-for survival, for calming down so I can see a different solution, for forgiving myself. I saw something printed on, of all things, a case of Mike's Hard Lemonade: "When you lose your sense of direction, find your sense of humor."
I think that sums up my view of the importance of a sense of humor quite nicely. Of course, dh and I are silly people