Having known a few people of those two physical descriptions, and quite a few people who've used psychedelics, in my small sample set you'd be looking at the wr

Having known a few people of those two physical descriptions, and quite a few people who've used psychedelics, in my small sample set you'd be looking at the wrong people. Change "long hair male" to "dreadlocks on a white male" and you'd have a point, but the majority of long-haired men I've known either wouldn't do drugs or are into non-psychedelics. And having spent a lot of time in clubs/festivals/house parties around drug use, of the many many users and dealers of psychedelics I've met... I don't think I could narrow down a single "look" that's more, or less, likely than any other. On the other hand, a) there is "a look" to facial expressions (not dissimilar to a weed "stoned" or amazed expression) that can be quite recognisable of somebody being under the influence - aided by things like super wide pupils and b) there are activities - such as being in a place where people are dancing to electronic music of some genre - where plenty of people use psychedelics and those faces can often be seen (though easily confused with expressions caused by other classes of drug).