>>9482
Well I typically just use pixiv, twitter and a bunch of boorus to find guro art. That, and certain japanese websites, like seesawwiki.jp and Pilot Suit Fetish. I don't know if there's any special trick beyond some basic detective work, using reverse image search, and knowing some japanese terms (which some anons have helpfully compiled on /art/).
All of these sites I came across through lurking on imageboards and my own browsing.