I type my stories on computer and then edit with a stylus on my iPad, and type the changes back into the computer again. It works for me.
I got the idea for my Werekids: Flight book and wrote the start of the story and the middle and kept it for a couple of years. When I picked it up again, I changed the start completely but parts of the middle are still the same.
Skills like good spelling and using capital letters and full stops in the right places are important for the final version of your story, but don't worry about them while the ideas are flowing. You should always re-read and edit your stories, so you can do it then.
When I'm writing dialogue really quickly, sometimes I skip all the speech tags (like "she says") and add them in later.
Step 1: Choose a really good flaw for your character. People get bored with nice characters.
Are they a little bit naughty?
Do they talk too much?
Do they never say what they mean?
Do they always say what they mean?
Do they ask questions and never listen to the answers?
Are they a know-it-all? Are they always offending people?
Step 2: Think about how your character behaves when they're angry, when they're happy, when they're excited, and when they have to wait.
Step 3: Repeat the steps until you have two to four flawed characters.
Step 4: Give your characters a problem and write about how they react and how other people react to them.
When I wrote my character Jake in the Zombies of Menzies Primary I was worried no one would like him because of his flaws. It turned out he was everyone's favourite. So now I try to make sure that all my characters are a little bit (or a lot) flawed.
Step 2: When something happens in the story, think about where it's happening. Where are the characters moving from or to? What sort of objects are there in those places that might be useful in the story?
Step 3: Think about what the characters would experience through their senses:
smells. (There was a classroom at my school that always smelled like feet.)
sounds. Can you hear birds or cars or a mouse scratching in the walls?
sights. Think about what you would see.
Werekids: Flight starts out on the Gold Coast where my Grandparents lived, so it was somewhere familiar to me. We also go there on holidays. When the kids walk to the park in the beginning of the book, it was a walk I had done myself.
If you're asking someone for feedback, ask them if they can ask you questions at different points in the story like:
"Why did this character do this?"
"What was happening to this other character at this time."
"Where were they when this was happening?"
"What could the character hear while this happened?"
"How did the other character react to what happened?"
In Werekids Flight: I started out with Pip's whole family being were-people. By the time I finished rewriting, it was only Pip who was a were-pelican and his family didn't know anything about it.