It is also important for you to begin your training with a brief contemplation on the "Four Protections" which the Enlightened One, the Buddha, offers you for reflection. It is helpful for your psychological welfare at this stage to reflect on them. The subjects of the four protective reflections are the Buddha himself, loving-kindness, the loathsome aspects of the body, and death.
The quote above is from Venerable Mahasi Sayadaw. Because of that passage, which I first read in 2006, I have made it a habit to begin a meditation session (even though I follow Ajahn Brahm's method) by reflecting on these four things. My question is: is this compulsory if one is practicing samatha and not vipassana (the quote above seems to be related to vipassana practice)? Can one start a meditation session without this preparation? I definitely intend to continue doing it, because I find it beneficial, however I'm just wondering if others do it and if it is required.
What I precisely do is this. Before a session, I first chant the "Namo Tassa" x3, then recollect the Buddha's nine qualities ("Truly the Buddha is holy, fully enlightened...), then the asubhas ("in this body there are various impurities: head-hairs, body hairs, etc.."), then I spread brief loving-kindness to all beings, then I recollect the five subjects for daily reflection ("I am subject to aging, I am not exempt from aging..."), and finally I reflect on the inevitability of death. And after that I start meditation proper, by practicing Ajahn Brahm's first stage of meditation called "present-moment awareness". This is what I've been doing before each sitting for a long time.
Do meditators prepare for a session in a similar way? Or do most of them immediately start meditation proper? Just wondering what folks usually do to get some idea.
Thanks in advance.