Breathing is a process that for, most of the time, takes place automatically and unconsciously.
We become aware of our breathing at times of stress. It’s commonly advised to “take a few deep breaths” when upset, to help you calm down, to take time to reflect on what to do next and not lose your temper.
This advice has been refined into a technique called Resonant Breathing. It’s easy to do:
‘Take five breaths per minute, and keep it going as long as needed. This means each inhale will last six seconds, and each exhale six seconds. That’s it!’
https://curiosity.com/topics/resonant-breathing-can-calm-you-down-in-a-matter-of-minutes-curiosity
It’s reckoned that this way of coherent breathing also reduces symptoms of depression, by changing the messages that the brain receives.
Controlling one’s breathing can also help you drop off to sleep. Known as the 4-7-8 Breathing Exercise, it’s a simple way of influencing one’s physiology and thought processes to move into a state of relaxation:
Close your mouth and inhale quietly through your nose to a mental count of four.
Hold your breath for a count of seven.
Exhale completely through your mouth, making a whoosh sound to a count of eight.
This is one breath. Now inhale again and repeat the cycle three more times for a total of four breaths.
Both breathing techniques are linked to yoga:
https://www.doyouyoga.com/the-7-best-yoga-breathing-exercises-both-on-and-off-your-mat/
Controlling your breathing might even help your writing….