I ask, why she does that this way, so I can learn, and yes, I then tell her, that this is cool and I'm happy to do it that way as well

But asking already is triggering a defense mechanism now... 😞

In general, we are perfectly fine though and very happy with each other
So this is not a real problem, just would like to do it better

Edit: and no, it's not about "my way"
As I said, for me this is just an external thing I'm doing and isn't connected to me - like it's not a personal fault, if I do it wrong
I often ask her for help, because I know she does many things better, where I can't

We have the saying, together we're one good monkey

It's just some things, and I'm not sure how to it better, when I want to tell her about my learning experience/mistakes I've already made, and want to show, that's easier or better that way
And even then, I don't say, that I'm doing it correct, I only say, I do it that way, because I think it's easier/better

And I usually ask, why she is doing something her way, because I want to verify my own approach - because I think, I'm doing something wrong or miss a thing, I haven't thought about

Edit 2: current example:
In our bedroom it's getting bright quite early and I said, maybe we should think about curtains, because the window blinds don't really work that good
She said, she is worried about mold on the walls with them, and I said, ah, yeah, you're right, I haven't thought about the winter months

So hopefully, you now have a better picture and don't think of my like an asshole anymore, that doesn't let any other idea being ok ;⁠-⁠)

Final edit:
I just saw now, that you aren't the guy I was talking with first
I was hoping for an exchange with another one, that is seemingly in the same shoes like my wife, so I can maybe have an idea how to do this better
That was the original idea, why I started talking
Maybe you have an input yourself, but at the moment, you misinterpreted my situation