i also don't go searching for plots or stories. whatever i do is based entirely on what i like that moment. i find i like ghosts, pirates, and indefensible arguments. just whatever seems cool to me. other things i find uber-titilating are abandonned ships/mansions in a state of decay, graveyards, anti-heroes/rogues-with-a-heart-of-gold characters, rediscovered objects fromt he past, and generally those things i can drive some pathos out of, such as a battlefield after the battle (not particularly interested in the battle itself, to be honest).
in a general story sense, i often aim for the aftermath of things as a start (see combinations of the above), and don't shy away from tragedy or tragic endings in the least. very, very rarely do any of my stories contain an idyllic setting, nor do i deal with many absolutes, and you could argue i'm overly dramatic. i have a stock character stable i'll use where i feel appropriate (that being based on how entertaining it is for me to write), and i often don't even change the names of characters from one story to another except for the MC/s. for example, 'Ola' will always be the loose cannon and betrayer, seemingly on one side of things but his unsanity brings him and those around him down (somewhat a variation of judas).
without detailing every single bit and part of these things, you get the idea, no? what it amounts to is i've got these, i guess you'd called them, 'internal templates' that shape the story. from there the setting and premise determines my plot. i'll always have scenes in mind before writing, and rarely do i start writing a story at his beginnings. as you can probably guess, i don't do much in the way of outlines.
on the flip-side, there are things i *don't* do as much as things that i do. for instance, if ever you find a child hero in the beginning of my story, rest assured he's there to be slaughtered quickly (unless that child happens to grow up quickly). rarely are my MCs happily married. i avoid mary sues as much as possible. and if ever i use a camaro instead of a mustang, there's a reason: the slut drives the chevy, the hero drives a mustang. my characters are rarely virginal, and i tend to avoid skinny body-types unless the story calls for it (this is just personal preference coming through: i like curves on a woman, lol).
that's why if someone gives me a timeframe, setting and genre, i'm off. the entire story is written around the very first scene i scratch down, be that scene the end or somewhere in the middle. from there i'm connecting the dots in ways that seem obvious to me.