Understand the structure of a limerick. A Limerick has five lines. The last word of lines one, two and five rhyme, and the last word of lines three and four rhyme.
Use stressed and unstressed syllables to create a pattern to the rhyme. Stressed syllables are those with emphasis when you speak them, while unstressed rhymes are not emphasized. For example, in the line "There once was a man from Berlin," the stressed syllables are "once," "man," and "lin" in the word "Berlin." So the pattern would be unstressed ("There"), stressed ("once"), unstressed, unstressed ("was a"), stressed ("man"), unstressed, unstressed ("from Ber"), stressed ("lin"). A limerick's first two lines use three stressed words, the next two use two, and the last can use two or three. Read this example aloud and repeat to learn where the stressed words are:
There once was a lady from Niger,
Who went for a ride on a tiger.
They came back from the ride
With the lady inside,
And a smile on the face of the tiger.
Pick a story and tell it, or describe a funny scenario about anyone or anything. Write out some words that are connected to the situation and see what rhymes work with those words. A limerick is meant to be fun, so come up with as many hidden meanings and puns are you can.
Look at examples and read them aloud to hear the pattern and rhymes. There are many books and online sources to choose from. Some Edward Lear examples can be found at the Poetry-online website. For kids, you might try the Giggle Poetry website. See Resources.