Morphologies of Shifting

Shifting can come from three parts of your body: your fingers, your hand, or your arm.
For small movements, like a half step or whole step, you can often shift using only your fingers.

As the distances get bigger, your hand and arm start to help more.

In lower positions, the arm is more active. As you move higher on the violin,
the hand becomes more involved.

To build a solid technique, practice each type of movement separately:

shifting with the fingers
with the hand
and with the arm

Then combine them.

Also pay attention to your finger angle. Flatter fingers create a warmer, fuller sound. More vertical fingers create a clearer, more focused sound.