Anime avatars are often a coin toss between (potential) comrade and chud, so it may be fun and maybe helpful to think about and share those in the place of that old bellwether for chuddery.
Mine is anyone with ".eth" as a suffix in their online name. I have yet to see a single person that does that that isn't a chud.
It may even be cheating, but seeing an actual cryptofascist cartoon "original NFT do not steal" is a pretty reliable red flag too.
EDIT: Oh yeah, I almost forgot.
another thing I've noticed is that some libertarians think that being atheist/agnostic is a trait of being socially "progressive", even though many of them still hold the same beliefs as religious conservatives (being anti-abortion, LGBTphobic, punitive view of criminal justice, etc)