There are two skills here rather than one: letting your body move and settle in its own way, and being able to steer yourself deliberately towards rest or alertness. It is worth having both.
Most people are strong in one and shy of the other. If you always take charge, your body never gets to finish anything on its own. If you only ever surrender to it, you are at the mercy of whatever state you wake up in. Breath is where the second skill is easiest to practise, because you can pick a direction and check within a minute whether anything moved.
Qur’an and Sunnah
seek help through steadfastness and prayer, for God is with the steadfast (Quran 2:153). Both are things you do rather than wait for, and neither amounts to gritting your teeth alone.
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُواْ ٱسۡتَعِينُواْ بِٱلصَّبۡرِ وَٱلصَّلَوٰةِۚ إِنَّ ٱللَّهَ مَعَ ٱلصَّٰبِرِينَ
You who believe, seek help through steadfastness and prayer, for God is with the steadfast
Qur’an 2:153read it in the library
Translation: M.A.S. Abdel Haleem, The Qur'an, Oxford University Press, 2004.
What the research says
A single thirty minute session of slow breathing biofeedback reduced performance anxiety in musicians facing a high pressure performance, compared with a control condition. That is one small trial in a specific setting, and what it does show is breath used deliberately to change state at a chosen moment. It says nothing about the other half of this, which is letting the body run its own course.
Wells R, Outhred T, Heathers JA, Quintana DS, Kemp AH. (2012). Matter over mind: a randomised-controlled trial of single-session biofeedback training on performance anxiety and heart rate variability in musicians.. PloS one doi
Strength of evidence: one line of research. A single study, or a theoretical account.
Why it works
Being able to move between letting go and taking the wheel is what flexibility in the nervous system actually looks like.
This one is still a draft. It is waiting on a scholar and a clinician to read it before it is published.
Near this one
To find the soft ocean sounding breath, breathe out through your mouth as if fogging up a mirror. Then keep that same slight narrowing at the throat with your mouth closed, and let the sound get quieter and quieter.
If you keep only one thing, make the out breath longer than the in breath. Four in and eight out is enough, and nothing clever is needed on top of it.
Put a hand just below your ribs and let it move. Most of us breathe up in the chest, and the settling effect comes from lower down, where the diaphragm can actually shift.