Fast forward 10 years, I came across my old cello (it was an intermediate cello around the $1800 range) and decided to pick it up again as a form of relaxation in college. I spent 3 months taking lessons with someone, but it was fustrating. The teacher basically had me play a new piece from the grade 3 suzuki book every week, and while progress through the books was quick, I felt like I wasn't improving. I ended up quiting towards of the end of the semester, mostly because of an increasing school workload.
I would still like to continue playing the cello whenever I have time. So far, all I do in my spare time is practising basic 1st and 4th position scales and pieces from the suzuki books. For scales I usually just play 1 bow per note, while focusing on intonation (I do cheat and use a tuner, though I don't obsess about it) and relaxing my hands (especially my left, since I have a tendency to tense up when trying to stretch my fingers).
Does anyone have recommendations for books on techniques, drills/scales and pieces of graduating improving difficulty that for someone around my level? I would honestly be happy just playing scales and drills, since my goal is slow gradual improvement whenever I have time to play.