Many people swear by it, but I suppose that occurs because most things are enhanced/elevated/amplified when intoxicated. A single note can sound majestic when intoxicated and thus your level of self appreciation is deceiving.

Art is a discipline and should be treated as such. I would recommend to clear your mind, meditate, and take a walk in nature if you can before you begin.

If you make tree's a regular part of your creative process you will not want to do it when sober, and will find it to be a dull experience.