I've been writing poetry for nearly 30 years, and in that time have written sonnets, villanelles, pantoums, sestinas and triolets. All of these use rhyme, except sestinas which have particular rules about how to use end words. These are forms that require a lot of patience and hard work, and they can easily go wrong. But you're dealing with poems that might only be 8 or 14 lines long. Short enough not to send you around the bend.
Unlike a rhyming picture book.
In order to use rhyme and rhythm effectively, I think firstly you need to be able to scan - to work out the stresses and/or beats in a line of poetry, and see or hear which stresses are heavy and which are light. You need to hear the rhythm and, more importantly, hear when it's wrong or clunky or missing something. It's not just about syllables, it's about which syllable in a word has the heavy stress. Important - the stress is on por. Icecream - the stress is on ice. It's easy to fool yourself if you're not practiced at it.
Some people can hear this naturally - they're able to easily and fluently use rhyme and rhythm to great effect. Most people have to work at it over a period of time before they get good at it. Secondly, you need to know lots of words. You can use a rhyming dictionary, but that can lead to some strange word choices, and it's easy to just find a word that fits the required rhyme when you should be choosing the best word you can. It's also easy to fall into the trap of inverting words to make a rhyme work. Walking across the paddock green. We don't talk like this anymore, and so it doesn't work in poetry today.
Rhyming restricts word choice. It's a huge challenge to write a good poem that rhymes and also uses great language in ways that add to the poem instead of detracting from it. Rhythm creates its own problems - again, it can be so easy to end up with a rhyming poem that has a da-da rhythm guaranteed to bore anyone to sleep. Put bad rhyme together with the da-da rhythm and you have doggerel.
When it comes to rhyming picture books, add all of those challenges on top of the crucial demands of writing a great story with engaging characters, a strong plot and less than 600 words ... it can become an impossible feat to achieve. So when I came up with an idea for a picture book story two weeks ago, and the first lines insisted on coming out on the page in rhyme, my heart sank. (See, now I'm using cliches as well!) I persevered, hoping that the rhyme would disappear and the story would emerge shining and new and without the rhythm that kept running through my head. Some hope.
I now have four messy versions of this picture book, four lots of different verses - and in every single version, the verses have a different pattern of beats/stresses. I can't even pick out the best and put them together because none of them match! The only thing that is saving me from running out into the street and screaming at the moment is that despite the rhyming curse that has struck me, I've managed to get a plot worked out - independently of the verses.
Now, this might not be you. You might either be really good at this (like Julia Donaldson of Gruffalo fame, or Lynley Dodd who writes Hairy Maclary stories), or a general rhyming whizz. You might be sitting there thinking what an idiot I am, and what is so hard about rhyme, for goodness sake. But if you, too, have tried to write a rhyming picture book and been driven around the bend, then you know exactly what I mean. Let's stop it right now, shall we? Or maybe I'll go back and have one more go at it...
(P.S. And of course now I discover Julia Donaldson has also written a picture book called The Rhyming Rabbit. But she has always been a song writer. That explains a lot.)