I’ve come to see mindfulness as a practice of living life with a greater sense of awareness. What we extend our awareness towards might vary, but I feel that the practice itself does essentially narrow down to awareness to a large extent.
On a practical level, this awareness relates to being aware of what we are doing and why we are doing it and then immersing ourselves into it. On a deeper level, this awareness relates to being aware of our oneness. This oneness recognizes human beings as not separate from one another and the universe at large, but deeply interconnected.
Whether on the practical level or the deeper level, this awareness translates into being mindful towards ourselves, towards others, and the planet. In this way, practicing mindfulness requires practicing self-care, it requires that we try to live a slow and sustainable life (mindful of the planet) as well as a fair and ethical one (mindful of others we share it with). Whether it is for practical reasons or for reasons rooted in the oneness I touched upon, I see self-care, sustainable living, and ethical living as components of a mindful life.
The hierarchies these components hold, work better when fluid. On both levels, there is a value in extending our awareness towards the most strategic priorities for the moment. So, at times our awareness might guide us to be mindful by being sustainable, while at other times it might do so by guiding us to be ethical at the cost of not being sustainable (using helicopters for rescuing flood victims for example). It also might guide us to prioritize our very separative self for the moment, as we navigate around the isolating grief and pain that we often feel as individuals in a connected system. In other words, practicing mindfulness requires practicing varying and fluid combinations of self-care and sustainable + ethical living.