The Rule of Three
A humor technique from the world of comedy.
There is a useful joke structure in humor writing called the rule-of-three. Here's an example of the rule-of-three which I've used as the greeting on my telephone answering machine: "Sorry I can't personally answer the phone. I'm either motivating thousands of people, appearing on the Oprah show...or taking a nap. Please leave a message and I'll return your call when I wake up."

Here's what makes the rule of three work:

A funny line is sometimes said to be like a train wreck. You know where the train (your train of thought) has been, you think you know where it's going, but then you're surprised when it goes off track. The same sort of thing happens when you see the unexpected slip on the banana peel. The surprise or twist helps build the tension to create and magnify the humor.

The rule-of-three structure sets a pattern like the train coming down the tracks. You'll see a similar principle in action in a two-person comedy act. The straight person sets up the pattern which the funny person's punchline will break. The rule-of-three structure uses this same structure. The first two items in the triplet set the pattern (the "straight" line) and the third item breaks the pattern (the curve/the twist/the derailment). Breaking the pattern heightens the tension and creates the surprise, usually resulting in laughter. There are countless patterns you could use:
Same Category/Same Category/Different Category (T-shirt which lists world-class cities: Paris/Tokyo/Fargo).

Expected Trait/Expected Trait/Unexpected Trait (She was pretty, she was shapely, she was a man).

Something Everyone Loves/Something Everyone Loves/Something Everyone Hates (A Las Vegas wedding package contains everything you will need; music, flowers, a divorce document).

Ordinary/Ordinary/Ridiculous (I go to Las Vegas to see the shows, eat at the buffets and visit my money).

Extreme/Extreme/Ordinary (Speaking to thousands, appearing on Oprah, taking a nap)

Rhyme/Rhyme/Rhyme (rhyming sets a pattern and can disguise or add a special twist to the third-item punchline). Here's an example I created for a 50th birthday party using the "answer first then the question" vehicle which Johnny Carson made famous. "The answer is꿚hree things that describe Suzie Smith. And the question is꿾hat are Nifty, Thrifty and Fifty." This example also uses the category Something Good/Something Good/Something Not So Good (people don't want to get older). I could have used the word Shifty as one of the first two words, but that would have been less effective setting the proper pattern.
Why three? It's just one of those tried and true rules of comedy. It's a rhythm that works. It's part of the music of the humor structure. Experiment and you'll find it's true...a series of three almost always works better than a series of two or four.

Use the rule-of-three technique and it will become a natural part of your humor tool kit. You'll find yourself to be funnier, you'll connect better with your audiences, and in only fifteen years you'll become an overnight success.