Yesterday I wrote about the resurgence of episodic fiction in children's literature. Books like The Penderwicks and even The Graveyard Book exemplify this trend. Both books contain stand alone episodes. However they don't include some other traits found in classic kiddie lit. It turns out that not everything found in those works of bygone days is making a comeback.
For instance, omniscient narrators still don't make appearances in modern children's books. The POV these days is almost very close to the main character. Occasionally, there will be multiple points of view, but those are tricky to do well. Instead, most books use a limited narration that is so close to one character's view point, that it almost can be written in first person.
Another thing you won't find in a modern kid's book is author intrusion (or interruption if you prefer that term). In my favorite of the Narnia books, The Horse and His Boy, CS Lewis makes the following statement (badly paraphrased from memory by me): "In Calormen the children were taught to tell stories much the way English children are taught to write essays. But while people want to hear the stories, I've never met anyone who wants to read the essays."
Now, that is probably my favorite example of all time of author intrusion. It's funny, witty, charming, and horribly true. However, it has no place in a modern children's book. For one thing, it breaks the fictional dream and pulls the reader out of the story. For another, it takes the story off into a tangent. Modern books are written in a more concise, straight narrative form. Author intrusions these days just seem to stick out. I've yet to see one in a manuscript I've worked on that hasn't needed to be cut.
And finally, the various -isms -- sexism, racism, ageism, etc -- are completely unacceptable in modern literature. Gone (mercifully) are the days of perfectly PC books, but blatant or even subtle -isms that aren't in a book to specifically show how bad they are are unacceptable. And you wouldn't want to read them anyway. Reading the sexism in the original Tom Swift or the racism in the original Nancy Drew made me want to gag. Although instructive from a historical perspective of how bad it used to be, there is no need to duplicate those kinds of stereotypes today.
So remember, regardless of the type or style of book you are writing, try to avoid weird omniscient narrators, author intrusions, and -isms. The editor that has to work on your manuscript will appreciate it.