In my first class, the instructor kept saying to breathe into the stretch during a long hip opener, and I had no idea what that instruction was actually supposed to make me do differently. I nodded along, moved through the rest of class, and mostly ignored the phrase for weeks, assuming it was just something teachers said.
Your first day
Starting takes ten minutes and four moves, breathing in and out through the nose throughout.
Begin in child's pose, forehead down, arms extended, and breathe there for five slow breaths. Move to hands and knees and alternate cat and cow with the breath, ten rounds, inhaling as the belly drops, exhaling as the spine rounds. Push back into downward dog, hips lifted into an upside-down V, and hold for five breaths, knees bent as much as they need to be. Walk the feet up to the hands and fold forward, letting the knees stay soft.
If a pose gives sharp or pinching pain rather than a stretch, ease out of it. Nobody's spine is straight coming out of a long day, so don't force the fold. A bent-knee fold with a long back beats a straight-leg fold with a rounded one every time.
The thing most people miss
I believed flexibility had to come first, that the poses would start feeling right once my body got more flexible. What actually changed my understanding was noticing, weeks in, that the poses I dreaded most weren't the physically hardest ones. They were the ones where I'd stopped paying attention to my breath entirely and was just holding my body in a shape.
Downward dog was the clearest example. I used to grit through it, watching the clock in my head. Once I started matching it to my breath instead of a length of time, counting nothing but the inhale and exhale, the pose stopped being something to survive. Depth had never been the actual goal. The breath was, and nobody had told me that directly. I'd just half heard it in a cue that made no sense to me at the time.
How you'll know it's working
The tell isn't a deeper stretch. It's a longer breath. Somewhere around the third week, downward dog held for ten breaths before my arms shook, up from five at the start, without me trying to build any strength on purpose.
What does it actually feel like when a pose and a breath move as one thing instead of two? That question doesn't resolve itself from reading about it, only from staying on the mat long enough to notice the shift. Sun salutations, which link these same four shapes into one continuous sequence, are where that question gets loudest next.