Write something you'd enjoy reading. Have fun with your writing.

The more you write the better you'll get. It takes practice, so try to write on a regular basis.

The more you read, the better your writing will be. Read a lot of different kinds of books, too.

When you're writing a story, you shouldn't think about what other people will think of it or whether it will get published. You should only think about making it the best story you can possibly write. That's all that counts.

REVISE-REVISE-REVISE

Try to get inside your characters' heads. When I'm writing a Humphrey book, for instance, I feel just like a small hamster. I've learned to think, feel, act and write like a hamster.

Once the story is down on paper, then you can go back and edit for various things. Sometimes I'll go through and just look at dialogue. Does everybody talk exactly the same? Or do they have distinct and different voices? Have I repeated information or words?

It's helpful if you can put you story away for a few days (or a few weeks) before editing. You probably won't have that much time. But if you put it aside for a little while and come back to it and read it, you'll see things that need changing. (At least I hope so!)

Go through it separately to check for spelling, punctuation and grammar.

I always go through once and check for overused words. The most common are: "but," "very," "suddenly," "really," "also,"... etc.

I also check for repeated words. You don't want words repeated in one paragraph and then the next - unless you mean to. (I only say that because in the Humphrey books, Humphrey repeats things on purpose - for emphasis- that's part of the way he talks.)

And of course, you want to check for logic. Does the story make sense? Does one thing lead to another?

Do you have dialogue? Or do you just say "this happened and that happened and then that happened." A common problem in children's writing is a lack of dialogue. But dialogue makes your characters come alive. It helps define them.

Read your story out loud. You'll catch a lot more mistakes that way.
That's at least a beginning ... and an idea of how much editing a writer does!