Let's start off where I begin with myself each time I sing, or whenever I start working with a new singer, at the beginning.
It really matters. Really. It's the material a singer makes art on, like canvas for a painter. Yet, somehow, it often gets neglected as its own entity in the "singer's machine". To a great singer, air has mass, weight, texture. You breathe it in, and it is part of you, and then you give it back to the world carrying your song.
In pursuing the study of singing, and the training of the voice as an instrument, the focus is often drawn to the outside - the end result of what is done with the breath. Students often miss the point here, listening to feedback and trying too hard to alter the path or form of breath that has already escaped their control. Muscular response follows, tricking them into thinking that force or effort is involved in control. I offer that we start the study of singing, and indeed our own awareness of our voices, from the inside. How do you embody air in the process of singing? Do you fear it? Do you hesitate it? Do you ignore it completely? Can you feel it? Can you own it? Can you share it freely, without shame? Think about it.
This is the beginning.