You breath out and wait for the moment that your autonomic nervous system triggers the in breath. You have to watch without watching. The goal is to observe your body breathing itself.
While the autonomic nervous system is all powerful, regardless of how long you try to hold your breath, your conscious watching of the breath is weak, lazy, easily distracted, unfocused and undisciplined so you miss seeing the in breath over and over again.
You may get a glimpse of your body breathing itself, but most of the time at your candle lit alter, you will visit old hurts, disappointments; have good and bad fantasies, virtually shop and plan for your future.
I aspire to do better, but mindfulness stubbornly stands apart from me. My mind races and shames me, daring me to not think. Not thinking, averting my conscious mind fills me with fear.
I have trained myself to be on the alert as my go to survival mechanism. A radar system that is constantly scanning my immediate area, my past and my future. On the look out for humiliation, embarrassment, loss of status, disrespect, ageism, anti-semitism, and hostility.
Allowing yourself to breath unconsciously is to enter a timeless space, to dwell in eternity and outside of history. You get a hint of immortality, nirvana... the path to the deathless.
Turning the hint into the answer unlocks the universe. I know that, believe that, but stay on the carousel anyway chained to a horse that takes me up and down and refuses to go forward.