Here’s a passage from my book Leap Before You Look.

Notice how you are already breathing in this moment.
Is the breath coming more into the upper part of the body?
Is it reaching the diaphragm?
Or is the breath reaching all the way down to the lower belly?
After just watching the way you are breathing for a couple of minutes,
Begin to bring some intention to your breathing.
With the in-breath,
Let the lower belly soften and expand.
When the lower belly feels full,
Feel the diaphragm expand with the breath.
Finally, let the chest and lungs fill completely with breath.
Hold the in-breath for a few moments,
Only as long as is comfortable,
Then let the air be expelled fully from the lungs:
First from the chest, then the diaphragm, and then the lower belly.
Just when you think you’re done,
Give an extra little push,
And you will find there is even more air to be expelled.
Hold on the out-breath for a few moments, before you inhale again.
Continue to breathe totally in this way for several minutes. (more…)