Tone production is getting better and better. Some variations of the vomit exercise are helping.
Recording and listening to oneself is a valuable exercise; good to do it this far in advance (just under a month).
When your teacher points out a funny thing you do standing up on your toes when going for high notes, and that’s weird because on the bass, the higher notes are actually–in relation to earth’s gravity–lower down, and your teacher points that out and then you keep catching yourself doing it and when you don’t do it your sound and your intonation accuracy are better, well, then, keep catching yourself doing that until you can stop it from happening, and then that’s a good thing to not do that thing anymore.
And if the expert editor of a book of excerpts has indicated a good fingering for a passage, it doesn’t matter what a teacher from 30 years ago said, it might be a good thing to try that fingering again. Maybe you’ve matured to a point where that fingering makes sense, and the one you’ve been using isn’t serving you anymore.
It’s not a bad thing to listen to King Crimson all day.