The most common reason people stop is that they made it too big. A daily practice that survives is short, fixed to something you already do, and undemanding enough that you'll do it on a bad day — which is the only day that actually tests it.
The general mechanics of building a habit — starting small, anchoring it to something you already do, and recovering from the days you miss — are covered in "Habits That Actually Stick." What follows is the part specific to a movement practice.
Same time, same place
Both help more than they should. A body shown the same sequence at the same hour in the same spot starts anticipating it, and the practice begins before you do.
Choose a sequence and keep it
Beginners often want variety. Variety means thinking about what to do, which is friction, and friction is what stops practices.
One short sequence, learned well enough to perform without deciding anything, is better. It also lets you notice changes over time, which a constantly shifting routine doesn't.
Expect it to feel like nothing at first
The first weeks are frequently unremarkable, and people conclude it isn't working.
What's usually reported later is subtle and cumulative: standing differently, noticing tension earlier, finding it easier to settle. These arrive gradually and are easy to miss while they're happening.
Learning the movements properly
Video teaches the shape; it can't see what you're doing. The corrections are the part that matters, and nobody can watch their own alignment.
A few sessions with a teacher before settling into solo practice is the usual route, and periodic check-ins catch drift. Online works well for this — the movements are slow and the camera sees enough.
Where it goes
Most people who sustain it describe something unspectacular: a fixed point in the day that belongs to them, and a body that feels better than it did. That's generally what's on offer, and it's enough.