Of all the exercises of yoga, probabaly the most important are breathing exercises. They are known in the East as 'pranayama' - a word meaning 'energy control'. This fact is significant, since breathing exercises helps us control more than just the air we breathe: when we breathe we also breathe in energy.
Hence breathing exercises are the fines way to enhance our energy levels, gain greater magnetism and mental force, and to raise our energies to higher levels, gaining psychic abilities, inspiration and more elevated consciousness in the process. This is not a vague thing, but a very definite one, as anybody who has practised yogic breathing exercises for any length of time will attest.
The book Realise Your Inner Potential contains a series of yoga breathing exercises devised by a Western Master of Yoga, Dr. George King. There are just six exercises, and they are very simple to perform, yet they form a complete system, which can be practised every day with ever greater results.
Dr. King also provided another, more powerful, version of the same exercises for the serious student. Using powerful visualisation practices these kundalini breathing exercises are also contained in the book.