Having a good technical foundation will definitely help you when you are learning the cello! If there is one important foundational skill to remember about playing the cello it is to keep the thumb of your left hand under your middle finger AT ALL times.
(Think “C” for cello, making a c shape with your hand where the thumb is in the proper location.) This would also include if you are stretching, shifting, staying in closed position, and even if you aren’t playing the 2nd finger your thumb will still remain underneath where your 2nd finger would be. I know some may argue that there could be a little bit of leeway on positioning. However, I’ve found that students are better in tune AND can often have a larger stretch the more tucked underneath the thumb is. On the flip side it is really hard to stay consistently in tune for extensions if your thumb is not in the right place. I often find that the student is either out of tune or will complain that certain fingers are hurting.
Try it out on the cello. First, stick your thumb under the 1st finger. Now try to stretch your pinky out as far as possible while your 1st finger and thumb stays anchored to the spot. Now move your thumb under your 2nd finger, or even your ring finger (cello 3rd finger) and observe how much farther you can reach with your pinky. You will notice a significant improvement in your stretch.
Being able to move your thumb will also guarantee that you aren’t squeezing too hard with your thumb. This can often cause pain in the thumb joint, or soreness in the muscle. A lot of times if you feel stiff or jerky while you are shifting it can commonly be because your thumb is squeezing too tightly against the fingerboard.
So the next time you are playing the cello, double check to make sure that your left-hand thumb is in the correct position! I guarantee that your intonation will be MUCH better and you will find that you can find and play the notes with ease and speed! Let me know if you have any questions about your left-hand thumb position!