I have a lot of characters I’ve spent time creating and developing, but I cannot, for the life of me, develop an overarching plot. Anyone got any techniques or tips on this? I know the question is nonspecific, but anything helps.
If you know your character well, list the things that the character wants and needs. Then devise situations in which you as the author prevent the character from getting those things, at least in the short term.
Jody wants to be King. But Sam wants to be King as well. There can only be one King. Jody needs to be noble and to play by the rules. Sam, not so much. Sam thinks up dirty tricks to make Jody look bad. Jody works to avoid/rebut these tricks, perhaps with some negative blow back to Sam. On one page torture Jody with nasty tricks and on the next page help Jody to overcome the tricks. Keep ratcheting up the tricks until Jody is crowned or figures out being King is not as desirable as it once seemed.
There's a very good book called The Anatomy of Story by John Truby. If you can get your hands on it, it talks about developing the plot, characters, the world and all of that in an organic way so you don't end up with very detailed characters who aren't tied together by anything.
The key is figuring out which character in your stable of characters is the one you want to change. Give him a flaw that hurts himself and others, decide on how you want him to turn out - a new person or worse off than before - and then think about the key event that happens to changes him.
Once you have a character that is hurting in some way, psychologically financially, physically, socially, and you know how you want him to be at the end, and you make him real enough to have a desire that he wants to get by the end, a plot will take shape. You'll come up with enemies and allies and all the other details that are either going to help or hurt him.
This is how I think about it. In terms of one specific character undergoing an interesting change and all the events/people that facilitate/hamper that change.
Even Iron Man. Selfish weapons-dealer changes into selfless hero. Why did he stop being a weapons dealer - someone used one of his weapons against him. Who? Terrorists and his business partner. Did anyone help? His friend, secretary and an old man in a cave. How did he change? He became a weapon... but this time, a weapon to protect the weak.
I like plotting to the point that I over-plot. I keep changing the character flaws and then the whole story ends up needing a re-tweaking, but I rather that approach than just starting to type and realising 50k in that I'm not writing a story but describing a series of events.
Stephen King I think is the most famous author who writes with only a loose either of what he's writing about, but Stephen King is also famous for having some not-so-great last thirds where you start to tell, "Oh... you didn't plan this out at all, huh."
Proceed with caution. Fanfic authors are great at figuring it out as they go, but they are working with guidelines, and still you see some of them reach 200k and stop when they run out of road because they didn't decide on an end goal.
If your characters are good, you might not even need to develop a plot. But you do need to know your characters very well and have good imagination.
Have you listened to children making up stories? They don't have a plot, but they do have some well-defined protagonists (a princess, a knight, a superhero, a supervillain etc.) and a world where this story is set. If a child has good imagination and patience, this can become a very interesting, a book-worthy story. The plot elements are coming in on the fly, and author only has to keep "weaving" the story.
In adult authors, this approach is known as "pantsing". You don't build your plot beforehand, you just keep writing and see where the story would take you. And here is why I believe that good imagination is important. Without imagination, we might end up with some good interaction between the characters and good dialogue, but without a story. Imagination helps author create inciting incidents and unique situations which have a good change of growing into a solid plot.
One method is:
Start with the world. What world/setting is in your mind? Next ask, "In this world, what does the villain want? Why is he doing what he's doing?"
You can follow this up by asking "What obstacles would the villain place on the hero, to prevent the hero from stopping him?"
That might give you a vision for a plot.
Hope this helps. I developed this way of thinking from Dan Brown's masterclass.