Good list from RichardR.

Ellie, your story is similar to mine. But i started cello lessons toward my 15th birthday with an ex-major symphony cellist. I made very good progress for the 28 months of lessons and then he vanished - no more lessons past middle of my senior HS year. But I continued playing cello on and off (violin was my major instrument). On my own I worked thru Saint-Saens and, Elgar, Haydn C major (I had studied the complete Haydn D major with my teacher) and some of the Dvorak and played some orchestra and a lot of chamber music - but rather intermittently as a cellist until my late 60s. Finally, in my late 60s, due to this website I learned of Victor Sazer's book "New Directions in Cello Playing," and bought the first 2 editions (2nd edition was issued shortly after I purchased the 1st). I found his book very helpful in assessing the way I played (my posture and technique, if you will). I played in coached chamber music sessions for 7 years and met with enough approval to know that I was doing things right. I'm old enough now to be glad I can still do it at all - I assess that I continued to improve until I was 72 (a decade ago) but not since. I'm afraid the people I play with would agree - but no one has said anything about it.

In my opinion (about which I am not humble) a teacher must allow you to play your instrument in ways that are compatible with the way your body works best in doing so. Teachers who do not allow for this should be abandoned. It is my understanding that much of the great Russian "school" of violin playing allowed this - and look at the results they got.