There's no cookie-cutter description. But I'd start with anyone looking Middle-Eastern...
And I was commenting that YES, 9/11 was a conspiracy. And the Muslims were the conspirators, not the CIA and Elders of Zion And White House etc...
...19 amateurs with box cutters taking over four commercial airliners and hitting 75 percent of their targets, that feels like a conspiracy theory.
This is the quote that I forgot to put in my post. This is what I was commenting on, insofar as 19 amateurs. I would ask any of those conspiracy nuts mentioned in this article, "What EXACTLY does an amateur suicide bomber look like?".