You can always try the "Woodchuck Burst". Thump an open string followed by a hammer on, then pluck the other open string and hammer on the octave. Voila! Four notes! I came up with this, because I didn't know what double thumbing was at the time, so I did what it was I
thought I heard, and ended up "inventing" a technique, or so I've been told by people like Titus, Dickens, etc.
