The secret in comedy writing is association. Let's see how this technique of association generates hilarious result. By association, means by pairing or combining thoughts, images or even words together.
The most popular and obvious form of association in comedy is INCONGRUITY; by pairing of opposites or contrasts. Like fat and thin, black and white, new and ancient and the list goes on. By juxtapositing two opposites it creates incongruity. This premise can whip up endless potential humorous ideas. Examples like a tall reek-thin man standing beside his rotund wife, a caveman using a handphone, a smart-talking donkey with a dumb owl or a devil having a friendly round of poker with an angel. As I've said before "anything goes". But of course not all incongruities will produce funny result.
Another obvious source of incongruity is the OXYMORON. Oxymoron is a figure of speech in which two seemingly contradictory words are combined. Examples like: open secret, good grief, original copies, small crowd or alone together.
Similarly to the technique of incongruity, is the REVERT. Here you take a normal situation and reverse it into its opposite. The most popular example is the bride carrying her groom into the room. Just take any ordinary situation and turn it around and see whether it can engender laughter. Like instead of having a bird in a cage, have a man in a bird cage, with the bird watching outside. "Anything goes"!
Use the association technique to light up your creative fuse and set it ablaze with ideas. Spur your brain to make new connection or new associations with opposities that will attract laughter.