Are you certain that "some new techniques" is really what you need now? How about some new ideas? A really great video for the latter is The Bass Guitar of Jack Casady. He and Jorma Kaukonen do somewhat-abridged versions of a handful of Hot Tuna songs, and after each go back through the song section by section and "break it down," with Jack explaining (sometimes with Jorma's help) what he is doing and why, how he's responding to things Jorma is playing, and so forth. Stuff like when he decides to move from an upper down to a lower register or vice-versa, when to play more melodically and when to play it straight, stuff like that. There are plenty of cool little technique bits scattered about, but that isn't really the point. Plus, Jack's dry sense of humor makes the whole thing vastly entertaining. I can watch it over and over and pick up new ideas every time. Just a thought....