How I use “FLOW”
I use the term to describe any psychological or emotional process, basically, as by its default state it moves freely when it is not blocked or resisted and not tangled up as a psychic mass, unconscious and in a relative state of psychological inertia. I'm not really using Mihaly Csikszentmihalyi's use of the term (author of Flow: the psychology of optimal experience), where flow is used to refer to an elevated, superior, elusive or hard to reach state that you enter when all aspects of you (emotional, physical energy, mental energy, intention) are in sync and unified at a given moment via your focus, and the resulting state(s) of this.
I find the term “flow” useful because it's very inclusive, and describes the fact that all psychic energy is pretty much always constantly in motion, even when it appears relatively inert. It's just that it tends to be looping in a nonproductive way if it's still accessible by conscious awareness, and when it does become truly inert, it tends to become a subconscious “mass”... at which point it becomes relatively if not completely inaccessible.
Not only does "flow" in this context also refer to “physical” energy flows, or ones that have a more physical component in nature (as energy running along with the nervous system, etc., "qi" in traditional Chinese medicine), but it also can refer to flows that transcend the psychoemotional aspect altogether. (This is the basis of Viking-Z, which is a pretty damn obscure system of "secular" magick// is constantly changing every handful of years anyway// he barely explains anything to the reader, if you can't make sense of it, tough shit I guess?)
Here, flows above the level of “thought” are referred to as “fire” flows, following the traditional cosmology of Western magickal practice, where Earth = physical, water = emotions, air = thoughts, fire = ???. Fire flows are like fast running, potentially destructive and difficult to control, and are universalizing energies. An example is creative and intellectual inspiration, like when you get an idea and it hits you like lightening, or any kind of "divine inspiration" where there's no conscious thinking or working involved in it. At that moment, you're in the realm of universal flows (whatever barriers of mind you normally have been relaxed if not disrupted temporarily). Thinking here only occurs at the level of psychological decoding or translation as separate process, and so is something that can be done moreso within the relative isolation of mindspace (if a relatively separated mindspace is still intact). The writer also places high energy impulsiveness in here, as well 'charisma' as a process.
***When you're in the universal flow, actually, you'll be a lot more efficient here and the amount of "inspiration" you'll be able to receive and to handle all concept will be exponential, if you have relative control over the machinations of psyche. Because hey, you still need one to function and do the shit. (There are more thoughts to explore here about why "genius", as we understand it to be, can be dysfunctional ... explained within this framework.)
He also explained enlightenment as a sort of flow rather than a permanent, ultimate state of being, which I found pretty useful at the time that I picked this up (over 10 years ago at this point, actually), and also as a sort of cleansing, high-energy state/process, which tends to be destructive by nature when it comes into contact with more inert, weaker processes. (Our thought and emotional processes as we mostly understand them to be, as they exist within the isolation of mindspace.) So when your psyche disintegrates or collapses, it's replaced with this energy, at least temporarily.
Not everyone makes it out of this kind of energy/ flow in a functional piece though.