Initial structure- how much or how little?

How much structure do you typically have when you begin writing (short story or a novel)? Do you have the whole plot outlined, every twist and Chekhov's Gun planned, all the scenes decided and just waiting to be transcribed? Or do you take it all in flashes of inspiration, scribbling down an idea that really sticks, and then let the story carry you away from there, adding and subtracting elements you think up along the way?

The idea just came to me a few days ago, of a man receiving a mysterious phone call and subsequently getting wrapped up in...something, so I wrote that scene right away. Then I thought that the factory the character on the phone mentioned in passing could play a much larger role...one that would make the protagonist recoil in horror.

All these ideas are really vague and sketchy right now, but I have the feeling they can really go somewhere. I just ask this question because everything I've written before has been pretty structured before I even touched a pen or a keyboard. So, fellow writers, where do you fall on the spectrum?

How dare you disrupt the sanctity of my soliloquy?

I usually know only a few parts of the story, mainly those that are connected to the idea that inspired me to write that story in the first place. How I go from A to B and then to C is something I figure out on the spot.

Of course, that means that the stories often end up somewhere totally different than C because all those things that I add on the spot get in the way, but that's more a case of bad plotting than anything else.

I just wing it. I let inspiration decide what I want to write, and planning to put the pieces all together.

I know key plot points, and of course I know my characters like the back of my hand, but the plot itself tends to just kind of coalesce.

I'll hide your name inside a word and paint your eyes with false perception.

While I usually know the ending (though it has happened that I've changed my mind on it while writing) and a vague outline, I try not to structure the story too much before writing it. A lot of the plot will grow naturally during the writing, and it's no good trying to limit it.

It's good to plot out the major events beforehand, otherwise it's easy to wind up with a story that's just "This happened then this happened then this happened" without really going anywhere or having any purpose.

I'm all over the spectrum. Every story I've ever written was written differently. Sometimes, different arcs within the same story are written differently. Sometimes, different parts of the same chapter were written in radically different ways.

For me, sticking to one way of doing things tends to go stale pretty fast.

Depends on the story, though generally I usually just have the general plot, certain character roles and certain aspects of their planned development, key plot points, and the general setting worked out. I like to leave enough room to expand and adjust if I need to. Basically, a very skeletal outline. Depending on the genre or tone, I may structure it a bit more. If chapters are more episodic or the story more comedic, lighthearted, or slice-of-life, I'll generally have less preplanning. If it's something more complex like a drama or mystery, I'll have more planned.

Out of everything, I usually put the most planning into the setting and characters first. Most of the time, the plot or lack thereof will write itself once I get a general basis.

“DAMMIT WHEN I HEAR 'SPACE CQC' ALL I CAN THINK OF IS BIG BOSS WITH A FISHBOWL ON HIS HEAD, STRANGLING AN ASTRONAUT OUTSIDE THE ISS."

The first thing I do is try to get a feel for my characters. They generally evolve during the writing process, but until I have at least their initial states I don't really have anything.

For plot, I have a general outline, but it's subject to change if actions I previously had planned don't fit the characters. In all cases, the plot should be bent to fit the characters; never should the characters bend to fit the plot.

As for setting... all that I really need to know before starting is the general feel of the setting. It seems to be a common trap to get bogged down in all the minutiae of the setting, but spending months obsessing over the exact caliber of the guns used or the exact mechanics of the different schools of magic or the precise number of people who work at the company where the story is set or whatever else is really a waste of time. Such details aren't crucial to the story or characterization; they aren't what's going to draw your readers in; they shouldn't be important to you while writing them; why put off starting to write while worrying over them? If a small detail actually manages to cause a plot hole, then that can be taken care of in editing anyhow.

Never build a character piecemeal out of tropes.