Find Your Best Idea.

You probably have an idea already, but you should work on refining it. Here’s how: Google “children’s book” and a phrase that describes your book. Once you’ve found books that are similar, look at the summary of those books. Figure out how your book is different than the published ones… The trick is to have one twist for your story that makes it different. If it’s a story about bullying, perhaps your book tells the story from the point of view of the bully! Or if it’s a story about a dog, make this dog a stray or blind in one eye. Maybe your story is different because you have a surprise at the end, or maybe it’s different because it’s for an older or younger age group, or your character has a magical guide like a fairy or elf to lead them through their journey. Just add one twist that distinguishes it from other books. – Book Fox

Write the Right Length.

What’s the right word count for your book? This is probably the most common question I get asked, and it’s also the one that most writers get wrong. Ultimately, you need to figure out what age range you’re writing for, and then write within that word count. – Book Fox

Really Get to Know Your Target Audience.

Writing for children brings a completely new set of challenges–something an author for grown-up fiction and nonfiction doesn’t have to be concerned about. In essence, the book will have to appeal to two completely separate and different groups of people:

• • The children that consume the book, and
  • The grown-ups that purchase and read the book with their kids

The age of the main buyer of children’s books is between 30 and 44. Females make up more than 70% of these buyers. A few ways you could really get to better know your audience are:

• • Spend time with age groups you’re targeting
  • Talk to parents and teachers
  • Give a survey to women within the target age range from your own social circles
  • Remember, your book will have to please parents and teachers just as much as children. – Kindlepreneur

Include the Most Important Elements of a Children’s Book Story.

Your unique and inspired story idea is only as strong as the way in which you tell it. Good stories are carefully designed and tend to be simple. It’s all about composition. There’s a beginning, a middle, and an end. There are actions, scenes, and emotions. And be sure to be clear about your core message. The five most mentioned elements of a children’s story are unforgettable characters, suspenseful action/hook, realistic dialogue, a clear storyline, and the “instant recall factor”. – Kindlepreneur

If a sentence doesn’t contribute to plot or character development, delete it.

– Writing Children’s Books for Dummies Cheat Sheet

If you find yourself using a lot of punctuation (!!!), CAPITAL LETTERS, italics, or bold, chances are your words aren’t working hard enough for you.

– Writing Children’s Books for Dummies Cheat Sheet

If your character hasn’t changed at the end of your story, chances are he isn’t yet fully fleshed out.

– Writing Children’s Books for Dummies Cheat Sheet

If you can’t tell your story in three well-crafted sentences: the first one covering the beginning, the second one alluding to the climax (the middle), and the last one hinting at the ending — you may not have a complete story yet.

– Writing Children’s Books for Dummies Cheat Sheet

Don’t let your story be preachy.

Your story should be subtle enough to convey a message without the moral being “in your face.” Kids can smell morals. And they smell like Brussels sprouts. – Today.com

‘Show’, don’t ‘tell’.

Writing picture books looks deceptively simple—after all, how hard can it be to write a 32-page story of about 700 words? (Most picture books are between 500 and 1000 words). In fact, though, it is this very economy of words that challenges a writer most. The craft of writing picture books involves telling your story in as few — and using the most potent — words possible (don’t get me started on why rhyme makes this even harder!) Keep it short and keep it “to the point.” – Today.com