Eckheart Tolle wrote in The Power of Now about our many paths to consciousness. He calls them portals and reminds us that they’re doors (in)to ourselves.
One of these portals is breath, as is (physical) sensation, intense focus on an object, etc.
Breath is great because not only is it always with us, we generally don’t have a lot of thought associated with it, unlike sensations (pleasure and pain), and objects (like / don’t like this flower).
He also reminds us that one conscious breath is enough to connect us with ourselves.
What’s a consciousness breath?
Simply focusing on the sensations of breathing, i.e. focusing your attention fully on what it feels like to breathe in and breath out.
Just one breath, and voila, you’re here.
Enjoy.