The method
Nothing exotic.
Just attention, practised on purpose.
In practice
You don't need the room to look a certain way. You don't need the moment to be perfect. The practice starts when everything else stops.
When the body stops moving, the mind gets easier to observe. Not quieter, necessarily. Just easier.
You don't need a cushion. You don't need a posture. A chair will do. The floor will do. What matters is that you've stopped doing everything else.
Anywhere will do.
You're already breathing. You always have been. The practice is just to notice it. To let it be the place you put your attention.
In. Out. The breath is the thing the mind keeps coming back to. Not because it's special. Because it's there.
Slow if you can. Don't force it.
The mind will wander. It always has, and it always will. The practice isn't to stop it. The practice is to notice it has wandered, and to bring it back.
That returning is the whole thing.
Wander. Notice. Return.