A really cool resource out there for all string educators is the String Pedagogy Notebook, put together by Michael Hopkins of the University of Vermont. Basically, it is everything a music educator needs to know about string instrument technique, with great articles and video examples. The double bass videos are very useful even for current students of the bass. I especially like their vibrato video.
In addition to specific string pedagogy techniques, Hopkins give some valuable advice on teaching in general. Sections on teaching technique include characteristics effective teachers, verbal and non-verbal delivery, introducing new routines, the power of routine, and classroom management. If any students are looking for an interesting project to reference for a class, I would definitely recommend checking this out.