When it comes to writing flash fiction, there are rules. Apparently.
I've read many articles by flash fiction writers about how to write the genre of short fiction (flash fiction is usually considered to be a story of less than 1000 words) and I've written and published some flash myself. Maybe it seems arrogant or foolhardy, or perhaps I was just naive at the time, but I did not read articles on how to write flash until I was already writing it—and getting it published. I just sort of happened to start writing it as part of an online community of flash fiction writers I got involved with on Twitter. Friday Flash writers posted links to their stories on Twitter with the hashtag #FridayFlash. I read a few stories and then dug into writing my own. I've been writing them for awhile now, even though I no longer have time to post them to blogs (note that if you want to publish an original story somewhere, most magazines consider something you have published to your blog or website as previously published and they will either not accept it, or pay you a lower reprint rate).
I only recently decided to read some articles in order to post them to a writing group page I run on Facebook geared toward setting certain months of the year aside to write short stories (sort of like November is set aside for writers to write novels during National Novel Writing Month, ie. NaNoWriMo). ShoStoWriMo is a group of about forty short story writers on Facebook who try, from time to time, to set aside a month where we will write short stories all month long. No rules, just write. You can write a story a day (if you're superhuman), or a story a week, or write one story for the whole month. No worries if you don't finish or your story turns into something longer. The goal is to write. Short stories and flash are the focus, but as we writers all know, sometimes the seeds grow into towering oaks instead of bushes. But the deal is we begin with short story or flash ideas and plots.
So I have been scrounging the interwebz for cool and informative articles, YouTube videos, and TEDTalks about writing. Writing in general, but mostly writing short--short stories and flash. Flash can further be categorized into really really short forms such as drabbles (100 word stories) and micro-fiction (stories from 1-to-500 or 750 words). I've found some really good articles and have been myself reading them for information and to see whether or not they are good enough to post to the group.
There are dozens out there that give "rules" for writing short stories and flash fiction. Personally, I'm a fan of the W. Somerset Maugham quote that "there are three rules for writing but nobody knows what they are". He was speaking of novels, I believe, but the same can be said for short stories and flash. But if you comb through the articles out there you will find more geared toward "rules" for writing them than sand grains on Miami Beach. Other writers have twisted the words of Picasso to say say that you need to know the rules of your profession (writing) before you can break them, though, I think the famous authors were referring to grammar and punctuation rules rather than form and substance (or art). Most of the articles I've found on rules about flash tend to focus on form and substance. And those rules can go straight to hell in a cookie tin, as far as I am concerned! To tell the story that your guts demand, that your characters COMMAND you to tell, sometimes you have to say "fuck you" to the rules.
One of those rules that I trash frequently when writing flash stories (at first because I didn't know the rule, and then now because I want to) is that you can't begin your story at "the beginning." You need to start it in the middle. Or even at the end. I can understand the whole "start in the middle" idea. It's a flash or a short story so there isn't a lot of room for plot devices and character arcs as you'd expect in longer works of fiction. I've never quite mastered telling a flash or short beginning with the ending, however. And not beginning at the beginning? I don't understand what that means, really. I mean, you can take any story really, and start it somewhere, but when you read about the characters and plot you realize that even beginnings are not the "actual" beginnings. There must have been events that happened even before the first words of any story. So, beginning at the very beginning just doesn't happen, at least that I have seen in short fiction. I am placing a challenge upon myself to try and write a short story from the very beginning at some point in my career. (The egg cracked and the World walked out...something like that). I believe it may be possible to write a short work from the absolute beginning. And should you? My stories always begin however the first sentence forms in my brain. I may change it later on, but that is how I write.
Should a writer never begin a story at the very beginning? I say, "No." Begin your story wherever you feel it needs to begin: the dragon taking her first flight or breathing her first fiery fumes, taking her last breath to pass on wisdom to a younger generation, or from the first view of her world as she steps forth from the cracked egg. (There I go cracking eggs again!) I believe the only bad way to tell a story is not telling it at all.
Whenever the story begins in the writer's head... That's the best time for the tale to start.