From your post I realize I don't know what a flow is. I thought or assumed it was memorizing steps, and getting them in order, same order every time.
What is a flow?
Kinda true, but there’s a visual pattern to most flows that makes it more kinetic than a list... here’s an example... but I don’t have a graphic editor handy to draw it as a picture...
And inverted L works for a bunch of things in a Cessna cockpit. From the fuel selector on the floor up through the cowl flaps and wing flaps, to the mixture knob, then turn and go left across the prop, throttle, carb heat, and keep going over to the mags, and primer.
Okay you “see” that upside down L shape now, right?
Engine failure...
Fuel on both (reach to the floor, start the L shape), mixture rich, prop full forwards throttle open, carb heat on, across and check mags and that the primer is locked.
Okay it’s not the “perfect” by the book engine failure checklist, but it hit all of the items in one physical easy to remember pattern. Just start on the floor and draw the upside down L. Everything you touch on the way up and across might or might not have an involvement with engine failure, but you’ll check each.
There’s other flows that work in other cockpits for other things. This is just one example.
In the twin, a go around started at the throttles, and then went left to the gear handle, then back to the flaps, and worked its way around in a circle to the cowl flaps, and then back to the throttle quadrant to set final power on the turbos... you could do it all faster than the checklist, but also without ever missing anything because the items went in a circle to the left.
Then, of course, you’d follow up with the checklist and confirm.
Sometimes there’s no good way to flow something and you’re just practicing doing “memory items” in a particular order, even if they’re shotgunned all over the cockpit physically.
But often you can find a way to move your hand(s) in a predictable pattern that will accomplish all of the immediate “must-do” items without flinging hands everywhere in a seemingly haphazard way. (Even if you know what you’re doing, it can look haphazard or unplanned.)
A flow, when one works well or well enough, can be enough to both get all the items done in a reasonable order, as well as be a visual checklist in and of itself. I can’t start the Cessna one on the floor without noticing that the fuel selector isn’t in the Both position, and I know that’s the usual position for engine troubleshooting... you see how it works as a memory jogger under stress, probably. Make sense?
Some flows I don’t like to call flows because they’re literally all over the place. Only the ones I can actually make “flow” around the cockpit do I call, flows. Others may disagree due to how they were trained.
It’s not a big deal how you define what’s a flow and not called a flow, other than it’s a memorized series or movements you can do in the cockpit without really needing too much thought about where your next step is.