sharke
I'll tell ya one thing I've noticed about marijuana. I don't smoke it very often at all, in fact maybe 2 or 3 times a year, but when I do I'm always surprised at how much better the instrument separation sounds in my mixes. Like if I have a project in which I've been struggling to give tracks their own frequency space and being unhappy with the results, I will listen to it stoned and all of a sudden everything is clear and well defined in its own place on the soundstage. I really don't know why that is but its interesting.
This is exactly why it should be avoided while mixing. Anything that makes your mix sound better without your actually doing anything, well, that thing is not your friend. Sweet-sounding hi-fi speakers, bass-hyped headphones, mood lighting, sex on or under the console, and all perception-altering chemicals.
Best combination: mix completely sober but encourage listeners to smoke a joint before listening.