This is a great question, @shaleco. Thanks for asking it.
I used to feel imposter syndrome a lot more than I do now and I think the key change I made was changing my identity from “expert” to “learner” and practicing “not knowing” instead of “knowing.”
These days, I don’t feel like I know anything. I’m always not knowing. If someone asks my opinion or for advice, the only thing I know is that “I don’t know” will be part of the answer. Oh sure, I’ll have ideas and excitement and experiences to share, but the underlying framing of all that is my not knowing. And that’s because I don’t know So. Many. Things. (What a strange relief it is to unburden oneself from knowing.)
To start identifying as a non-expert/non-knower, I rewrote my website bio, which was peppered with achievements, and instead revealed and thanked all those that helped me along the way and downplayed my role in achieving this or that (which was the honest-to-goodness reality of it anyway). I also started describing projects more honestly, focusing on sharing all the things that didn’t work instead of glossing over those things, which is what I used to do.
I’m not perfect at it and there are still times that I make myself out to be some ideal version of myself, but it’s becoming second nature to be more humble and honest, which is way way better than any sort of false sense of security I ever got before.