The main asset of the limerick from the writer's point of view is that the structure is well defined, the form is short, and the rules quite clear. For an amateur such as I the idea of devising my own form is too brain-aching to contemplate. Most traditional limericks tend to be of the "There was a ...." sort. They don't have to be of course, but here are three examples, the first two "anon" and the third by me.
There was a young lady of Wantage
Of whom the Town Clerk took advantage
Said the Borough Surveyor
"Of course you must pay her
You have totally altered her frontage"
There was a young lady of Chichester
Whose form made the saints in their niches stir
One morning at matins
The heave of her satins
Made the Bishop of Chichester's breeches stir
There was a young lady of Bude
Who went to the beach in the nude
She avoided the grab
Of an itinerent crab
And smacked him for being so rude
