For me what enhances the music most is...better equipment. Seriously though, lights off does it, as does lying down, even though it puts my ears at the wrong angle. Oh, and I actually prefer having my wife with me, whether we're making our own music or not.
Close your eyes and hear the music ?
It seems like music sounds better when I close my eyes. Some people claim that it sounds better with their glasses on. Someone once told me that if someone suggested that music sounded better in the nude that a large group of audiophiles would swear to it! What makes music better for you ?