Examine the poems in Stevenson's A Child's Garden of Verses, and note the simplicity of their construction, the music of their rhymes, and their clear, direct method of statement—the latter an essential if children are to be interested.
One of the reasons for the appeal that "Hiawatha" makes invariably to children is its direct form of statement, with few involved sentences; and its eight-syllable lines.
Eugene Field's poems on childhood themes, and some of the passages in "The Forest of Wild Thyme," by Alfred Noyes, are delightful examples of the possibilities of 8.6 lines with alternate rhymes.
Merely to break up prose into lines of irregular length, is not to produce poetry.
There must not only be beauty in individual lines and phrases, but there must be beauty of idea and form in the verses as a whole.
At the same time, never sacrifice sense to sound.
Young writers sometimes say to me, "I see so much, and feel so much, yet I cannot put it into words: the thoughts are beautiful while they are inside my brain, but there seem no words adequate to express them; I am baffled directly I try to put them down on paper."
Don't despair. Every poet has felt the same: but let it encourage you to recollect that many have got the better of the feeling, by hard work and sheer determination. After all you have all the words there are, and the most famous of poets had no more than this to work with. We sometimes forget that in the end, the greatest writer that ever lived had to reduce everything to the same words you and I are free to use.
You may remember that Mark Twain once went to a well-known preacher, who had delivered a magnificent sermon, and, after extolling it and thanking him for it, the humourist added, "But I have seen every word of it before, in print!"