How does one tell a good joke? What makes some jokes better than others? These are good questions with no specific, definite answers. There is no exact formula for telling a good joke. If there was, many comedians would be out of work.

The most important part of any joke is the delivery. How you tell the joke. This includes many things like the tone of your voice, body language, and any pauses during the telling of the joke. Anyone telling a joke needs to display confidence throughout or the audience will be less likely to believe that it's funny no matter how good the punchline is.

You need to know the whole joke before you begin to tell it. Having to stop and think in the middle or backing up to fill in information that you left out will greatly reduce the effectiveness of the joke.

Something else to keep in mind is to decide whether or not you will offend anyone in the audience. In my opinion, if you are going to offend someone (or the audience as a whole) you need to be aware of it and make it obvious that you intended to offend. Offensive jokes can be very funny but accidentally offending someone is only effective at, well, offending someone. Make that decision before you start your joke or routine. If you are going to attempt a stand-up routine you need to determine your stance on this before you even start developing material.

The punchline is where everything should come together. For a punchline to do it's job it should be unexpected or, at least, not obvious before it has arrived. If your audience knows what the punchline is going to be then the joke is, technically, over before you finish it. There is nothing wrong with a joke that makes the listener think to understand but if you have to explain it to him or her it will, most likely, flop.

Comedy is a difficult field to define what works and what doesn't work. Many jokes have been expected to be sure things until the audience responded with silence. Practice and experience are really the only ways to have any certainty that your jokes are funny.