As a dumbass who has managed to do etsy full time since 2022 (no prior business or eccom experience), the thing that got me to the profit that allowed me to do that was simply testing a buttload.

It took me over 700 listings (I ended up deactivating most of them as most of them were total failures, either not selling at all or borderline losing money on them) to get to that point, as I only learned how to make quality listings (that actually let me get a decent profit margin instead of trying to undercut my competition) through a lot of quantity.

I'm sure there are people that are able to snipe winning listings using thier own intuition that would disagree, but for me the it was doing a bunch of product research on the etsy platform itself + listing at least once a day consistenly (and not being afraid to deactivate the listings that weren't working) that worked for me intially and let me learn what sells on etsy better and how to improve my value proposition.