No matter if you are using a sponge or shoulder rest, correct placement of the violin on your shoulder is really important.
I always say that the scroll should be pointing 45 degrees left of center. You don't want it too much in front, this will make the
job of the bow staying straight much harder.
One big issue for younger students is where they should put their head. Yes, it's called a chinrest, but we don't actually want the tip of our chin to rest on it.
A lot of teachers will call it a 'jawrest' instead and I like this much better. I like to say that the lip of the chinrest should fit snugly under the jaw with maybe a
slight tilt left of the head. Some teachers will also say "turn and tip", meaning that you'll turn your head to the left before placing your jaw on the chinrest.
Don't overdo this though, you don't want to end up looking like you are trying to take a nap on your violin.
Your left arm should comfortably 'hang' under the violin. It's a good idea to look for two triangles. One is made by the underside of your arm, your side, and
an imaginary line drawn from elbow to side. The other is from your shoulder down to your elbow and up to your wrist. Nothing should collapse. Keeping this
space will create a good habbit for later use.
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