Not as easy a question to answer as to ask, in every country Buddhism has visited, it has mutated or taken on local customs in some way. However in coming to the west it has also been subject to rational empiricism, which is the stance the Buddha taught to take.
As a western Buddhist I still received my grounding in Dhamma from Her Eminence Khandro Mindroling Rinpoche – a Tibetan teacher, and also from Kobun Chino Roshi (deceased) – who came from Japan and lived in America.
Now I take most of my teachings from the Pali canon, having reverted to a somewhat Therevadan stance on the purity of these teachings, whilst always being aware they were carried as an oral tradition for some few hundred years before being inscribed.
The Buddha’s teachings are quite explicit. To follow his path is to follow your breath and body until you still your mind. It is not to focus on the nose or mouth – this comes from a misunderstanding – but to “fully face” the object of meditation – at first the whole body breathing experience and sensation in the body, which one is to relax.
The neurological basis of this is simple. By sending a signal to the brain via the Vagus nerve, one of ten Cranial nerves and one that directly enters the brain stem near the fight/flight mechanisms of your lower brain, you tell the mind:
EVERYTHING IS OK!
And eventually the mind believes it. The endless, inane, babble and chatter of your own mind stops and, one day – if you are doing it right - something seemingly magic starts happening. You start to feel quite blissful. The Buddha said, “Enraptured with bliss” and “with a bliss not borne of the body”. He described four material states of bliss and four immaterial. The first four are essential to fully attaining the meditative fruit of “insight” or “Vipassana”. This fruit is one of the conditions of extinguishing the final remnants of the three root poisons and attaining the goal.
On the way you act with compassion, kindness, generosity, honesty and do right by those you meet on the way.
The goal is hard to attain but possible for everyone who tries hard enough, develops their insight, uses it wisely to hone their meditation, does not get hung up on anything, including views of the path or the goal .. and practices hard at meditation, with discipline and awareness yet with a relaxed and upright body.
That’s how I do it. I’m not exactly a meditation master (yet?) but I teach the basics and get good feedback. Don’t know why people write books on the subject to be honest. People need feedback.