Practice a long whispered “Ahhh” sound. The most important part is to relax and wait for the body to breathe in on its own.
On the exhale, think about softening the neck and jaw. Imagine the spine and head lengthening up to the sky on the exhale.
It helps to smile gently with your eyes.
You can practice standing or sitting, but lying on the floor in constructive rest is the easiest.
Practice 3 to 5 whispered “Ahhhs”— or whatever syllable feels good— and then watch your natural breath.
Repeat as many times as you like.
Body Project Blog: Where Thought is the Active Ingredient.