I'm mostly a "big scene vision" writer.
See...the vast majority of my tales begin as Epic Moments Of Enlightenment At The Most Random Moments.
I'm minding my own business, doing nothing in particular--when the inspiration hits me for particular "events" involving my favorite characters--usually intense moments of character growth, or larger-than-life action scenes (which you won't find in my short stories for a while...they're mostly character tales).
Then...as I reflect on this, I mentally form a plot around these scenes--how did the characters get to this moment?
Why are they doing what they're doing? And so on.
After this, I jot in my Black Book, not a
synopsis or
outline (those things tend to exhaust my creativity, I found out the hard way....), but a brief, one-page "teaser" (similar to what you might find on a hardcover-sleave, or a softcover-back).
Then, I reflect some more on possible "big moments"--and when I get enough, I start writing.
If I ever get "writer's block" (which is
so depressing, believe me

), I stop, and throw around ideas for restoring the "flow" of the tale....
Sometimes, I just get an idea for a first line (i.e. from my tale "B-4 and After": "B-4 did not understand"), and it intrigues me so much that I just start typing away, letting the tale "write itself" as I go along. But that doesn't happen nearly as often....