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. 
'Classical liberal' for sure
Also idk if it indicates full chudness, but in my experience pretty much anyone who says they're 'socially liberal, fiscally conservative' is a whole lot less 'socially liberal' than they claim
That usually means they are sex pests under pretense of "sex positivity" and like drugs.
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)