Writing must begin with an idea -- a thread of a thought that meanders itself into your brain and won't unlatch itself from the crust of your thoughts. It can begin on the train to work when the person next to you, who smells like rotten fruit, turns and begins a conversation about turnips. Or it can begin one day as you witness a child who misbehaves by shoplifting a shiny action figure from the toy store while their mom looks the other way. Or maybe, as boring as it may seem, the seed could implant itself in your empty brain as you hear a conversation between a gangster and his cell phone planning a meet to trade money for drugs. All that I have mentioned has happened to me -- even the turnip lady...the strangest people ride public transit -- me included.
The next step in writing? Well, transferring the idea to your computer microchip. I am a pantser. I don't do outlines. They're cumbersome to my writing. Writing should be fun and outlines are most certainly not. I take the idea and run with it typing (would never consider using pad or pen to transfer my thoughts...yuck) like a fiend. Scenes flow out of my brain onto the white screen creating worlds of fun that I never thought would be possible. The shoplifting child and neglectful mom have turned into a pair of thieves who steal toys for other boys and girls who don't have it as nice. The Turnip Lady, well she's an alien come to steal all of the turnips on our planet (not a really horrible thought) to bring to her planet whose people will die without them. And the gangster? He's a mobster's wife's boy toy trying to arrange an assassination of the mobster. All good beginnings to stories that may intrigue.
The final step, after all thoughts, dialogue, imagery, action, etc. have been tossed into the wide blue yonder of your computer, is revision. Revision -- ugh! If I have an enemy to my writing it would have to be revision. Many writers enjoy it. Well, not me. But, there is no getting around this step in your writing. Stephen King says that he spends hours upon hours of each day revising. If he can do it then there should be no reason you or I couldn't do it. So, you have your story. It's sugary sweet and cradled in your arms. Get ready to take a match to it because no first draft is beyond annihilation. Not even one written by Stephen King. Read it out loud...DO NOT BYPASS THIS AT ALL! Reading it out loud brings forth problems you didn't see before. Then hand it off to other writers (ask them first...of course) and not just to one person (your mother). When your peers return your story there should be red, blue, and/or computer track changes marks every where. Say thank you...VERY IMPORTANT...don't disagree with your peers or try to explain where they had questions...if they had questions then you didn't clarify it in the story. If there were opposite reactions try to appease both sides and figure out why it was clear to one and not the other. And then after the revisions have been made and it's in second draft form send it to another set of peers. And then to another and then to another...this last step is the hardest and takes the longest to complete but it's the most fulfilling when the final draft is ready for submission.
Good luck, and happy writing!