Whatever your initial idea is, write it down in small print in the middle of a sheet of paper and circle it. Surrounding that circle, you jot down all of the things you associate with that subject. Just the first things that pop into your head: What you like, what you don’t, synonyms, or anything that is most commonly associated with it. Circle each of those subjects, draw a line to connect it to the original circle. Then you repeat the process with each circle, Just like the word trees you may have done back in grade school. If you repeat the process long enough, you may just find two paths that cross one another.
Say I wanted to write a joke about religion. I’d write down everything I associate with it: God, beliefs, scripture, church, temple, etc. Branching out further and further, I find that one path goes Religion > Church > Sermons > Stories > Movies > Star Wars. But then, another branch might go Religion > Followers > Extremists > Fanatics > Toxic Fandoms > Star Wars. There it is… Same central theme, two different paths, same destination.
From there, I would brainstorm ways to make those two paths work in tandem. How I feel about religion, how I feel about Star Wars, compare and contrast, don’t overthink it, and here’s what I ended up with:
“I love going to church, even though I hate dealing with church people. For me, it’s kinda like Star Wars: I love the stories, I just can’t stand the fan club.”
Not my best joke ever, but I’m pretty proud of it.