Many people have the misconception that they can't add humor to their writing because they aren't funny. This is a myth. Humor can be learned. Humor has basic formulas that are fueled by what every writer has an abundance of: creativity. I'm living proof of that fact. Before I studied humor, I had no idea how to be funny. But now that I've studied some of the science behind what makes people laugh, I understand that humor comes from a combination of certain factors laid out in a certain way. I recognize it more in other people's work and I can add it to my own.
I'll give you and example of one basic formula that can be learned. One of the most basic ideas in humor writing is incongruity. When two ideas that don't make sense are put together it makes us laugh, whether it be in a character, a plot, or a dialogue. For instance, much of the dialogue in the movie, "The Emperor's New Groove" is incongruous. The two main characters are about to fall over a steep waterfall and the emperor asks, "Sharp rocks at the bottom?" And his companion very calmly answers, "Yup." Then the emperor replies straight-faced, "Bring it on." This dialogue is all said in the most calm manner, making us laugh because it is the total opposite reaction than they should be having to the scary situation.
An example of an incongruous character is in C.S. Lewis's "Voyage of the Dawn Treader". "Reepicheep" is the tiny mouse who is braver than anyone else and a swordsman that no one can defeat, yet he is the tiniest of all the creatures on Prince Caspian's ship. It makes us laugh when this tiny mouse shouts out huge threats at people in a squeaky little voice. The incongruity of someone who is in reality so tiny, but acts like he is ten feet tall is funny.
So if you want to add humor to your writing, but think you're not funny, don't be discouraged! Just take the time to study one of the many books on Amazon.com that teach the formulas for writing humor. It will be well worth your time, because sometimes humor is the edge that gets your manuscript to stand out above the others that are all alike in the slush pile. Good luck! and let me know how it goes!
Kersten Campbell, author of "Confessions of a Completely Insane Mother"