You've written some stuff. You feel good about your characters, you've got some action, but what drives your energy for showing up is exploring the deeper meaning of life.
Start with an unusual setting and some "different" characters.
Set the time.
Figure out your obsession.
Say it's with finding out who you really are, your own unique identity (insert your obsession). Generate scenes with that in mind ~~ the character's interaction with others, trying to figure out her place in the world ~~ that's better ~~ a universal theme for kids and all of us...
As you write, look for clues to finish the theme to make it thematically significant: how DOES one figure out his place in the world? Through trial and error? Okay. And so what, really, does that mean overall? Finding one's place in the world takes trial and error, but in the end....
The anwer to the ...above must be worthy enough for you to give up hours of your life to write, worthwhile to the character to go through the struggle of a journey, worthwhile for the reader to give up hours of her time to read your story?
Picture books, because they push away subplots, make the concept of plot is easier to grasp.
Take, for instance, Where the Wild Things Are by Sendax.
What is it? 34 pages? Many of which are drawings. I can't remember and I'm not going to get up and check, but lets say there are 17 pages of written language.
Beginning: 1/4 of entire project introduces characters while showing where and when the story takes place, and demonstrating a major character flawy that will help drive the action of the story (go to:
http://www.blockbusterplots.com/character-development.html for the character Plot profile info.).
In the Beginning of Where the Wild Things Are we meet Max, the cat and the mom. Max shows his wild side and drives everyone crazy.
End of Beginning: a scene signifying no turning back, entering the heart of the journey toward transformation
At the end of the Beginning of Where the Wild Things Are, Max is sent to his room with no dinner and there he watches his room turn into a forest or is it a jungle?
The Middle: 1/2 of the page count showing trials and errors, antagonists. Whateve keeps the conflict, tension, suspense or curiosity of the audience high.
Where the Wild Things Are ~~ journey to Wild Things, conquering wild things
Middle of the Middle: Showing an unsual world
Where the Wild Things Are ~~ shows 4 or more pages of covered with pictures demonstrating wildness
Crisis: Middle builds toward the 3/4 mark and the biggest scene of all
Crisis is a scene forcing the character to a new awareness.
Anything energetically higher than anything that has come before
Where the Wild Things Are ~~Max has everything, but he is lonely for love.
The End: Lots of significance toward the Climax.
Where the Wild Things Are ~~ journey home.
Cimax: The character "showing" the transformation
Where the Wild Things Are ~~ settles down to eat his dinner
One page of Resolution ~ his new life from then on
Where the Wild Things Are ~~ and his dinner is hot.
Of course for a novel, or screenplay, or historical you'd have lots of sub-plots that follow their own template as described above, but at a sub-level ~~ they are sub-plots, afterall.