One thing I learned is that a lot of people get a clever idea that gets them one laugh, then they drop it. The thinking is "I have a good joke there, so let me move on to the next good joke."
Wait. You don't just have a good joke. You have a good premise, too, and maybe that is worth three or more jokes.
A premise is an idea that can yield laughs. A joke is a specifically phrased set of words or sentences that elicits laughter. This difference is important because one premise can lead to many jokes. The world record in English for number of laughs in a comedy routine is 12. It was achieved by Phyllis Diller, an American comedienne (1917-2012) famous for routines about her appearance. All the jokes in that one minute were jokes about people being fat. Basically, that's one premise with twelve jokes.
"And that's just 12 jokes out of a career total of 50,000."
If you know the difference between a premise and a joke, you can go further with your ideas.
For example, the first contestant got a good laugh just from saying "I sounded like Donald Trump." The premise is the situation or her weaknesses are similar to something related to Donald Trump. Great, but is there more you can say on this premise? If sounding like Donald Trump is so funny, then explore the whole Trump range of expressions. For example, she could have said, "I was so angry with myself, I looked in the mirror and I said, 'You're fired.'" Since she was a US expatriate living in Korea, she could have made a reference to herself through the lens of Donald Trump's views on immigration. There was so much possible with a cultural reference everyone knew, and she could have had two more jokes about it.
Another speaker talked about her interest in Toastmasters, an international public-speaking group, as her cheating on her husband. "I'm seeing someone" and "My husband believes he is my first love" got some great laughs. Good metaphor, but she could have gone further with it. She could have explored more of the range of this topic. For example, she could have explored her embarrassment, sneaking out of the house, saying she could not come home early "because of work." She could have broken down and cried, saying, "I'm seeing other audiences!" Instead, she went on to other topics, other jokes, even political references, but the audience could have related to the metaphor more.
One common way this happened was people would come up with a new word, which got a laugh, but they would not explore the word.
I'll give you an example of my own. One time I combined the Korean word for an older woman, ajjumma, with the word mafia, creating ajjumafia.
Great, and it gets a laugh in some stand-up I have done, but don't finish just yet. Explore the implications of the new word you have coined. How are these elder women like Italian organized crime? You can definitely find comparisons, particularly if you have had to deal with the demands of this group in your workplace.
"Hey, Rico! You no eata kimchi. You no wear a visor."
By the way, the winner of this contest, Rodel Cuaton, did this. His speech was a huge number of jokes using a particular metaphor. He extended the metaphor rather than get merely one joke on it. He clearly had the biggest streak of laughs among the eight contestants.
"You want a shiny trophy? Read two books by Judy Carter and work your butt off."
So, you have a good joke? Great. What's the premise of your joke? How can you take it further than the first good laugh you got? Push yourself to come up with three or more.
-- Roger