9 times out of 10, I conquer imposter syndrome with something close to spite. At least that's what people tell me, I think it's just brutal honesty.
Most of mine comes from having worked with a writer who had more fans than me, and being a reader who constantly sees authors on the NYTimes best seller list, etc, etc. So a lot of it comes out of comparing myself to others. It had me in a really dark place a while ago. I might have given up writing if I wasn't surfing one of my favorite creator's channels on Youtube and come across some deeply thoughtful videos.
Now, when I start to feel like I'm inferior to somebody else, I remind myself that everybody is inferior to somebody. There's always somebody better. There's somebody they look to and say 'oh my god, why do people think I'm good when that exists'. If they don't let that get to them, how dare I consider it?
I also remind myself that I don't owe anybody anything. My work doesn't have to be 'good enough' for somebody else, entertaining enough for somebody else to enjoy. It just has to be something I enjoy writing, something I'm proud of even for half a second. The only person I should ever compare myself to is myself, seeing how I change over the years and improve. Because everybody started out somewhere. We're all on a different path, some people started with natural advantages and some people work their way through the hard way. It means we're all at a different place, and comparing yourself to somebody is stupid- because they may have been doing it for years longer than you, or may have learned from somebody spectacular, etc etc.
Once upon a time, all those big name writers were where I am now. I don't have to prove that I'm as good as them because they're father in their journey. And when I had fans who felt like they needed to be as good as me, I just laughed and papped their heads and told them the best thing they could do was keep writing.
It's helped a lot to keep my head above the water when it comes to imposter syndrome and depression. It may be spite, or it may be my hard-earned silver lining mentality, but it works.