So one of the things that came up in my little lesson the other day was that my vibrato could use some refinement. I use a really wide vibrato, intense all the time & it was pointed out to me that I could use a narrower vibrato & that I could do different things in terms of when I start the vibrato, or in terms of varying the note.
This is the sort of thing that I bet I do instinctively on occasion & I've definitely read various interviews with master cellists complaining about students just doing "on/off" with vibrato... I've got this sort of "everything as intense as possible all the time" mentality to making music ... it's an integral part of my style, but I've finally realized that I lack the ability to do more refined or quiet styles with ease (for example, playing mournful middle-eastern music or the "tea & scones" sort of classical/baroque music).
Part of this comes from being obsessed with the way Jacqueline DuPre plays, part of it comes from wanting to project/be loud & generally being enamoured with loud cellists (like Rostropovich), part of it comes from David Finckel's 80, 90, 103 Vibrato vid & practicing that only with a wide vibrato, and part of it comes from not really feeling like the narrow vibrato is a real vibrato.
On the other hand, watching the vid. of Steven Isserlis playing the Tchaick Rococo Theme Variations at the proms, the amount of things he is able to do just from vibrato is mind-blowing. The expressiveness and the uniqueness to what he's playing largely comes from this.
So now I've got something new to really pay attention to when I wath other peoples' playing ... and also something to work on in my own...