The Rule of Threes. Also called a comic triple, the concept here is that it takes two instances to establish a pattern, and then a final one to get a laugh by providing an third instance that is surprising or contrary to what the audience expects based on the pattern. For example, Jon Stewart has a line that goes, "I celebrated Thanksgiving the old-fashioned way. I invited everyone in the neighborhood to my house, we had an enormous feast... and then I killed them and took their land." What makes this line particularly funny is that he's set up a pattern of expectation for the audience. Everyone comes over to his house, there's a big feast... these are normal, everyday modern traditions of Thanksgiving, and then he throws you for a loop and goes really old-fashioned by making a commentary on the less-celebrated points of the Pilgrims' First Thanksgiving. Those two initial instances set up the audience so that the payoff is even funnier. Sure, the joke still works without them, but it's not quite as funny if you just say, "I celebrated Thanksgiving the old-fashioned way. I killed everyone and took their land." It still works, but not nearly as well. If you really want a joke to pay off, set up your audience by giving them two points of reference to manage their expectations first, and then knock them down with an unexpected payoff in the third.

The Rule of One. When you're paying off a joke, it should be the only thing happening at that particular time. That's not to say that other things can't be going on around it (and in many successful comedies, the narrative relies on more than one comedic subplot), but think about the ideal setting for telling or hearing a joke; it's when the audience's undivided attention is focused on the joke and the person telling the joke. Even if you have a story where there are a ton of things going on at the same time, make sure each payoff to each setup gets its own turn in the spotlight. You want your audience focused solely on the one line, sentence, or situation that's supposed to make them laugh.

A Laugh a Minute. In sitcom writing, it's actually more than that. On a show, it's not uncommon for every page of the script to have 2-3 comedic bits in it. And with your standard page averaging about 30 seconds of running time, that's actually a laugh just about every ten seconds. Pacing is incredibly important in comedy; you want to keep the audience lively and engaged and entertained. While a short story or a novel may have different pacing requirements, it's worth pointing out that there needs to be a lot of "funny" in your work to make the cut as a comedy. As a standalone genre, comedy should have the audience laughing almost all the time... if you're writing a story that has one joke or one gag every chapter, or with several hundred words between each gag, you might not be writing a comedy, but rather some other genre that just happens to have some comedic moments in it.

Choice of Words and Examples. As a writer, you have the freedom and responsibility of choosing the exact words you want to use. Comedy is certainly no exception. The words you choose and the examples you provide are often a great source of comedy (or indifference, if you select poorly). Some words, as a result of the way they look or sound, are automatically funnier than others. If someone asks you where you're from, Poughkeepsie or Lake Titicaca are more amusing responses than, say, Las Vegas or Denver. If someone asks you to name your favorite animal, a hippopotamus sounds funnier than a shark.

The Unexpected. The unexpected is always funnier than the expected. That doesn't mean what's expected can't possibly be funny or that the unexpected is automatically funny... but all other things being equal, surprising your audience is far more likely to get a laugh than telling them an answer or a punchline that they see coming. When someone asks you your favorite type of animal, most people will name a dog, cat, bird, or other house pet. If the response to someone's favorite animal is a dingo, or a manatee, or a penguin, the element of surprise is sometimes enough to get someone to laugh or chuckle. If you can find a way to combine it with a word or example that's inherently amusing, your chances at a funny moment are even better. "What's your favorite animal?" "A dog." "What about you?" "A blue-footed booby."

A Grain of Truth. Some element of truth to a joke makes it infinitely funnier. When an audience can recognize the authenticity or reality behind the situation you're poking fun at, it can oftentimes make or break the gag. Jon Stewart's joke about Thanksgiving (above) is funny because there's an element of truth to it, with the Pilgrims colonizing the area, inviting the Native Americas over to share a meal, then stealing their land. It wouldn't be as funny if Stewart's punchline were, "... and then I took them all to Disneyland" because there's no element of truth or reality to that punchline. If you can find a gag or a joke that has a foundation in what's real and true, the bit will hit home that much harder.

Rewriting. The maxim "writing in rewriting" is especially true in comedy. Very rarely is the first joke that comes to mind, or the first punchline you come up with the best version of that particular bit of comedy. Stand-up comedians hone their act over the course of dozens, sometimes hundreds of performances. When something doesn't work, they change it. When something does, they might still tweak it to see if they get a bigger laugh the next time. Similarly, sitcom writers work collaboratively in a room, throwing out jokes, playing off one another, and critiquing each other's writing until they're sure that the best possible version of a particular comedy bit is being shot for the show. When you're writing comedy, never settle for just the first thing that comes to mind... give yourself the freedom to think up a half a dozen different ways your joke can be funny, pick the best one, and then rewrite and rewrite some more until the execution is the best it can possibly be. There is often a stark difference between the first joke that someone comes up with, and the refined joke that someone has spent considerable time developing and refining.