Any moment is open to practice. While many moments will not be optimal or even feel like practice: Walking with an open willingness to manifest compassion, wisdom and selflessness is practice of the highest sort. It is a practice that transcends words or customs, it is a practice that manifests the pure fruits of our efforts (even when we see that the fruit is ocassionally bitter or rotten). All the cushions, retreats or mantras can not compare to that. Indeed there is little to compare!
Walking from your home to your car or bike; walking from the backdoor to the garbage; realization of a unique and fleeting moment with family; a slow exhalation followed by a joyous inhalation; pure simple awareness. These are all forms of practice that have no form or label. They appear within the home or at work from a nature that is not seen too often – a nature that blooms only once in a while but is constantly nurtured by its own fallen petals – a nature that is only seen in the periphery when attention is focused elsewhere. You can touch your hands together reverently after those moments in thanks and humility for the incidental manifestation of your practice in the wilds of the day. Monastics spend time altering their environment to provide a place that is open to practice. A serious lay-person allows their practice to seep from their very pores and drip from their brow. The fire of zazen is but a cool breeze during the heat of the moment.
We don’t need beads and accessories. Or to draw attention to our practice through the rustle of robes, the striking of a bell or the whispering of a mantra. My robe is a dirty pair of jeans, my bell is the early whistle of a train, my mantra is the constant step of my foot upon the earth. Zen does not need to make a dramatic entrance into a room. It silently enters and leaves with us, lost in a crowd, unseen in an empty room like perfume or a lingering fart.
Opening of a window brings in a breeze, and shutting the window does little to stop the wind outside. Neither can it help if your bodhisattva roomate decides to release a mindful one.