I love Buckethead. Currently, he is my favorite guitar player. His style is so varied that he is able to cover a huge array of emotions that I have never heard from another band or artist.
The following video is a "lesson" found on YouTube. I'm guessing it's taken from a DVD, but I do not know what. If you know, please share!
Buckethead shows a few different riffs with bizarre explanations. It really adds to his character. This is the video that showed me how to perform "nubbing".
John Taylor - guitar and bass instructor for Mile High Shred.