Mem Fox is an Australian children's book author and public speaker. Here are some tips she shares on her website for writing a successful picture book:
1. Trouble should occur at some point in the book.
2. It should be based on one of two themes: "The Stranger Comes to Town" or "The Quest".
3. Build characters whom the reader cares about deeply.
4. Perfect words should appear in perfect places.
5. Delight in happiness at some point in the book.
6. No preaching allowed.
7. Include subtle signposts to living in a social world.
8. The book should affect the heart of the reader.
9. Unexpected or unusual use of language should be evident.
10. The story should be complex, forcing the reader to remain attentive to detail, problem-solve, predict, derive meaning and roll over hills of emotion.
11. For younger children, establish an original pattern with rhyme, rhythm and repetition.
12. The book's effect should lead the child to cry: "Read it again!"
Collage of Mem Fox books courtesy http://1.bp.blogspot.com.