This is best done during your waking hours. Notice everything. Your next slice of inspiration could come from anywhere. Constant vigilance.
Keep running commentary about everything. Don’t let it be bland. For example (of what not to do), “Textbook. Pencil. Homework. Bored. Bored. Bored. Bored. Meeeehhhhhh. *Stretch of silence* Bored. Bored. Bored. Chemistry. Bored.” Make it interesting. Make it explosive. This serves the double purpose of both giving you writing ideas and decimating boredom.
Develop your idea.
This is best done at night while trying to fall asleep as there are no outside distractions, such as homework, colors, or pretty books.
Warning: This method will keep you up at night with ideas swirling through your head. Before you know it, it’s past midnight.
Warning: if you happen to come up with a decent idea, you’ll need to turn on the blinding lights, get up while being half-asleep (which is an accident waiting to happen), and write down your idea. Crud, it’s 1:00 a.m.…
Warning: this method will result in you being excessively sleepy the next day.
Fuel yourself with caffeine instead of sleep.
Blast music so you can forget that other humans exist.
Your best writing happens in the evasive “zone”. So you should wait to do your hardcore writing until you have gotten into the zone.
Start with flash fiction or a writing prompt or a blog post.
Edit previous writings.
Post the flash fiction/blog post.
Get distracted and respond to comments on your blog.
Get even more distracted and start reading Wikipedia posts loosely connected to your story, starting you on an inescapable trail of breadcrumbs and links leading you farther and farther away from your topic.
Take a break and get a snack. You deserve it. You’ve been so efficient. Beware: you’re leaving the zone and you have to get back to it in order to work on your short story. But it must be done because your hunger would also call you out of the zone.
Get back to the zone. This time it should happen faster, hopefully.
Read through your notes on your story so you don’t forget anything and accidentally break your established background information.
Read articles on writing because you’re a horrible writer and must discover the secret before you start because your first draft must obviously be as good as your favorite novel and one of these random internet articles must hold the key, despite them all saying the same things.
Write a little.
Delete it and try again.
Reread what you wrote yesterday and redo it.
Wonder at how your favorite authors magically think amazing thoughts and then somehow pull the right words in the right order from thin air and make a novel.
Reread your favorite passages from your favorite novels and marvel at the words.
Write a little more. Now you’re figuring it out. Hours pass and you don’t notice. Your characters and scenes and descriptions are perfect and everything is sunshine and roses and perfection. You don’t suck!
Edit. Reread what you wrote. You do suck.
Edit. Edit. Edit. Nothing may remain the same. Everything must be improved. The words awing, the story logical (or logically illogical). It’s unrecognizable from where you started. Seriously. It was supposed to be about a cupcake-zombie apocalypse and it’s morphed into a melodrama starring salmon.
Be proud of yourself. You did it! It’s awesome and done and you don’t suck!
Reread it. A little worm of dread wriggles inside of you as you realize it’s horrible. Delete.