I can’t stress enough how important it is to find the right chin rest and shoulder rest combination that is right for you. They are there not only to make vibrato and shifting easier, but more importantly for your comfort. After playing for the majority of my life with a chin rest that was too low, I’m now experiencing neck and back problems in my early 20s. I’ve been working with an athletic therapist who actually started out with a music degree, but it is much easier to prevent a problem than it is to correct it later on. If you have a short neck, you don’t need to worry about the chin rest as much and can focus more on finding the perfect shoulder rest. If you have a long neck, you need to first find a chin rest that is tall enough for you. Then experiment with different shoulder rests to match.