Your Fiddle and Your Left Hand

Sorry, ladies: those elegant left hand nails will have to go.

The fingers of the left hand should stand on their tips (that is why the nails must be short).

The thumb and first finger should work together as a unit (except when changing position, which comes later). For now, wherever they go, the finger and thumb move together as a unit.

A crucial technique is the ability to put the second finger in either a backward and forward position.
Here is a small gap between first and second fingers (2nd finger close to first finger).

Here is a big gap (2nd finger close to THIRD finger).

So the first finger and thumb travel together, while the second finger can either be a small gap or a big gap away from the first.

There are NO MIDDLE-SIZED GAPS!

Then the third finger goes down after the second.

The fourth finger goes down after the third. Try to keep it on its tip as far as possible.