First, Go Check Out...
I ended up listening, and meditating, to the included video at work and felt the results were really promising. I think that when applied properly, the teaching Matt Kahn puts forth can be extremely valuable.
Matt basically instructs us to BE the breath, saying that the reason we aren't at ease in life is because we have shallow breath, even holding our breath sometimes. This idea of breath relating to consciousness makes sense on a variety of levels, from athletes entering flow states, to panic causing hyperventilation, to great singers practicing breath work.
I've typically been a shallow breather, and have worked on it in the past to some degree, but lately haven't been thinking about it. One thing that I noticed really benefited my spiritual practice in the past was running was running. It used to force my lungs open and improved(or helped me reclaim) my lung capacity, which could be a major reason. There are a few practices I've found helpful, keeping these in mind with the teaching in the post above helped me get right into the feeling I think he's going for:
Nasal Breathing
I picked this concept up from "Body, Mind, and Sport," by John Douillard and found further support from the show Stranger Things whenever Eleven would call someone "filthy mouth-breather."
In my experience, breathing into certain areas activates related areas. When we breath into our mouths we miss out on some of the mucus membranes in our nasal cavity that in my experience send the breath towards the head.
Take a look at the picture on the right, notice there are multiple turbinates. The nose is more complex than it appears, with multiple sinuses and complex structure. I don't think we fully understand how it works, and I am definitely guilty of using my mouth to breathe, especially when I'm even slightly congested.
Not to mention, almost all other animals normally breathe through their noses.
Full Body Breathing
This one I learned from the book "Initiation Into Hermetics," by Franz Bardon:
The skin has two functions: to breathe, and to secrete or eliminate. Therefore we can consider our skin to be a second set of lungs and our second set of kidneys.
[...]concentrate and think that not only do your lungs breathe, or inhale air with every breath you take, but the entire body as well.
Following this line of thought, the whole body can breathe in the air all around us. So when I practice this meditation, I keep that in mind and try to think of breath entering through my whole body, not just into my lungs. If anything, this works on an energetic level.
In previous chapters, Bardon recommends brushing the skin with a natural hair brush to wake the skin up. I use a boar bristle brush in the mornings when I have time.
Breathing into Tightness
Sometimes, when I breathe in I find tightness or blockages in certain areas. What I've found when focusing on these and really breathing into them is that for the most part they're made up of trapped gas! Once I get a burp or two out from concentrating the breath in the vicinity of tightness, the area clears up.
Kind of a funny thing, but I think passing gas is vital for clearing out toxins. Try it out! See where your breath wants to go, and if it's not getting there, explore why. It's simple, but effective in deepening the breath and clearing up discomfort.
A good belch is really satisfying, just ask a kid.
Breathing Taller
This one is fairly basic, just breathe towards better posture. Combined with full body breathing, this provides a simple way to diagnose our posture. Generally I've found my posture mirrors the depth of my breath, if I'm not breathing into a certain area some of my muscles aren't engaged.
It makes sense, without breath getting to our muscles how can they function properly? We should be breathing so deeply that every part is nourished.
For example when my head is tilted forward and shoulders rounded I'm not getting enough breath in my chest. Or sometimes my lower back rounds or slacks from sitting too long or something. When observing my breath I noticed I wasn't breathing into my stomach enough.
This can work both ways too, by just getting into good posture, my breathing opens up. So standing tall with my chest out and rib cage tall opens up my chest for easier breathing.
These are a few techniques I've picked up over the years. After reading the post by 