One of the trickiest parts of a story is knowing which slice of an infinite series of interrelated events (i.e., the Universe) to look at. You can’t start at the beginning (i.e., The Big Bang), unless the nature of your story is tied to the beginning. Similar case with starting at the other end of things. Most likely whatever story you want to tell can be narrowed down to somewhere within the tiny slice of time that encompasses a single person’s life.
The length of the work you’re trying to create matters here, because IF you’re trying to create a work that spans an entire person’s life, then you really don’t have any more decisions in this regard. Start with their birth, end with their death. Fini.
On the other hand, if you’re trying for a specific word count, that will narrow your search for the start of the story considerably. Even the best writers can only convey so much information in a certain word count, and the lower your word count needs to be, the more precise you’ll have to be when picking your beginning.
Let us say in this case, that you’re writing for submission, and you’re trying for a story that is 3,000 Words or less. That’s pretty limited, depending on what kind of story you’re trying to tell, and what kind of characters you plan to use.
One mistake that many authors make is trying to start their story on a perfectly average day, to let the readers know how things normally are, then to move on to more interesting things from there. Don’t do that. Your readers already know what an average day is–they’ve had quite a few of them themselves.
Start where things get interesting. That way, you’ll have your reader’s interest right off the bat. With a limited word count, you need to get through things quickly, which means rushing through parts of the overall story, while zooming in closely on others. You want to rush through the boring bits, and zoom in on the good bits.
With erotica, that typically means glossing over the character’s entire life and background, and focusing on a single encounter. With horror, it’s basically the same deal. None of the details of the character’s life are worth focusing on, unless they make the story move forward.
It doesn’t matter that your main character’s name is George S. Klein. It doesn’t really matter where he lives, unless the setting is unique enough to warrant a significant fraction of your tiny (3k is succinct, in my view) word count. If it’s necessary to mention that he was born and raised in El Paso, Texas, then mention it, like I just did. Then move on, as I’m doing.
Most writing advice is telling you to “Show, Don’t Tell,” and that’s good advice except when it isn’t. Sometimes, especially when constrained by word count, it’s better to just tell the readers some stuff, to sum up.
Here’s the start of my story “Past The Bullshit”:
“If we could just cut through all the usual bullshit, and you’d just let me put this in you,” he indicated the thick bulge in his pants. “Well, then you’d know.”
“I’d know what?” She was mildly amused by the man so far, and she sipped her drink to facilitate that feeling.
He shook his head. “There’s only one way to find out.”
It was the wrong line, to the wrong girl, on the wrong crappy night, but somehow, less than an hour later, she was in his hotel room, on his bed, her skirt pushed up to her hips as she let him lick her into readiness.
I could have introduced both characters, and I could have written a dozen pages or an entire book on how and why they ran into each other in that bar, but none of that mattered for the story. All that matters for the story is that this strange man gives this woman a strange and crude line, and against her better judgment it works. Then the action takes place, then the resolution of both the introduction and the action.
All in <775 words, in this case.
Here’s the start of my 2500+ word story The Octopunishment:
Bridget Walsh brushed aside tentacle after sagging tentacle. They were dormant for a time, and this was her only chance to escape. She’d had such chances before, but needless to say, she was still here. Naked and dripping, she climbed up onto the thick layer of rubbery flesh, escaping the sea for a time. She was on the skirt of Kýrios Chtapódi, the Lord Octopus. In order to escape, she had to climb all the way up its enormous body, all the way to the head, which rose like a mountain into the sky.
It isn’t fair. The thought nagged at her once again, but as before, it never did her any good. Yes, it wasn’t fair. Why should it be? Everybody knew that life wasn’t fair; why should afterlife be any different?
I could have started the story chronologically, and taken my time. Under different circumstances, if I needed to pad the word count or flesh out the story more, I would have. I could have started off at the point her life took a fatal turn, the day that Zeus showed up in disguise to the game show she was hosting. I’d have had the opening bit be about her thinking that this one of her guests was weird. I’d have had her insult him (part of her routine), and I’d have shown the man transforming into an angry Greek god who kills her with a thunderbolt. I’d have shown her arrival in the particular Underworld that the king of gods condemned her to.
But the project didn’t call for all that–I wasn’t trying to write a novel. I could have, with this story, and that’s the problem. You have to know what story to tell, which moments are important. In this story, the important moment is a decision that Bridget makes when she reaches the summit of Kýrios Chtapódi, and she has a chance to escape. The character is on a specific journey in this story, a specific challenge, and I started the story where the challenge begins.
Everything else that the readers needed to know, how Bridget ended up where she was, the details of her kinky torture at the hands of the Lord Octopus, and everything else that was necessary for the story, I told in flashbacks here or there as she climbs up the side of this mountainous creature.
Start where things get interesting. You can always backfill details later.