Diaphragmatical breathing

The single most important thing I was ever taught is breath control and from there the path to peace was laid.

With empty and relaxed lungs (the state after a normal out-breath and not the state of complete exhalation) you push out your diaphragm and gradually inflate your chest up to your neck, just like if you'd been filled with water, the air fills the bottom and gradually up to the top. Then you allow the diaphragm back in, pull it closer to your spine and you expel the air up emptying the top of your lungs and throat last. The exhale should take longer than the inhale did.

You'll instantly be more relaxed and you'll also be sitting much straighter. A very good part of the cross legged pose you see many of the yogis and deities in is that is straightens the spine and makes this breathing easier. One good way to sit that is not too hard and also does not look too out of place in public is to just raise one leg up in a cross-legged position as the other hangs down normally - this is enough to straighten the spine.

Sitting and straight spine aside you should be able to incorporate the full diaphragmatic breath into any part of daily life; Waiting for a bus, elevator, web page to load, any time when you may be fretting, toe-tapping or stressing - breathe instead.

This breath control is very calming and healthy for mind, spirit and body.

It is useful to be aware of breath, this constant flow of life, you breathing from birth to death, is often short and shallow and this is always when you are stressed. Make correct breathing a habit then naturally you will be more relaxed and able to handle life.