Relaxation Technique

The more I discover about High Blood Pressure as a condition, the more I realise that it has to be controlled by a combination of strategies. In the majority of cases, certainly in the upper bands of Hypertension, medication alone is unlikely to control it, nor diet or exercise in isolation.
I have been experimenting with some relaxation exercises, involving breathing at a steady pace of about 9-10 breaths per minute whilst listening to gentle music. Whilst there is a definite improvement in BP readings immediately after this, I am not sure yet if there is any long-term benefit. However, even temporary reductions are worthwhile if they are taking some pressure off the body. I guess that prayer, meditation, yoga etc would have similar beneficial effects.
I would be very interested in other people's experiences.