Listen, if you do enough, it doesn't really matter where you are
. But the common wisdom is a dark room, because then there's no environment to act off of and what you see can easily take its own shape in the darkness. That said I prefer tripping in the sunlight / outside for emotional reasons and feel no lack for visuals.
I don't want comfort. I want God, I want poetry, I want real danger, I want freedom, I want goodness. I want a clever signature.