Jokes, you see, are plots in miniature. Stories sealed up and ready to go. You’ve got your beginning, middle, end, your conflict, your characters – flaws and all. All you’ve got to do is flesh it out. Expland on it. Change gender and setting if possible. And no, it doesn’t have to be funny because many jokes (indeed, stories) need an element of tragedy to make comedy (and vice vearsa) and you can just crank up the aspect you want to emphasize.
Here’s a joke that gave me an idea for a radio play I once wrote “The Angel of Trafadden” (see urls to podcasts listed on sidebar)
“It was Ryan’s funeral and the pallbearers were carrying the casket out from the church. When they bumped into a pillar, one of them heard a moan from inside the coffin. They opened the lid and found Ryan alive. He lived for another ten years before he properly died. Another funeral was held for him and, as the pallbearers were carrying out the coffin, Mrs Ryan shouted “Now, watch out for that pillar!”
OK, it’s the way ya tell ‘em… But the point is that they don’t have to be the funniest jokes – just so long as there is a story in there, a universal truth with which your readers will react and engage. Wordplay/puns won’t work so well, go for the story…
Here’s another one you can chew on for a story idea (it used to go down well in the creative writing classes I taught in an English prison…)
The defendant knew he didn’t have a prayer of beating the murder rap, so he bribed one of the jurors to find him guilty of manslaughter. The jury was out for days before they finally returned a verdict of manslaughter. Afterward the defendant asked, ‘How come it took you so long?’ the juror said, ‘All the others wanted to acquit’.