There is a commonly-held idea -- I don't know how old it is, but it's definitely ancient -- that there are only a limited number of plots for stories. The exact number that supposedly exist varies depending on who you ask, but the two most commonly-given numbers are 7 and 36. Just to get you acquainted with the idea, here are links for The Seven Basic Plots and The Thirty-Six Dramatic Situations.
The idea I'm talking about is a related one -- namely, if there are only a certain number of plots available, the stories around me must be using them. I read and like a lot of those stories. Now -- and here's the radical idea, if you can have radical ideas using the same old plots -- if the stories I like most use the same basic plot, then it follows that I can safely "borrow" that plot for my own use. After all, if there are only 7 or 36 or even 2000 plots, the vast number of books that have been written over the years must be using borrowed plots too.
It's a simple -- and logical -- idea that immediately raises a red flag. What about plagiarism? There are laws against copying other people's work, you know!
If you look over those plots, you'll see that they're pretty generic. If you pick a story you like and simplify its plot to its most basic form, you get a generic plot... and the story itself gives you some ideas about how the twists and turns of the plots might be handled. The more stories with this basic plot you read, the more ideas you get.
You can try taking the story and replacing the main character and the world in which the story happens. This will drastically change the plot if you're creative with your choices. (You might get some ideas for that process from my Asking the Right Questions post.)
There are plenty of ways to take a story and turn it inside out. Here are some examples:
- Take the Rags to Riches plot (from the 7 plot list) and reverse it to a Riches to Rags plot.
- Or start at either extreme and travel From There to Boredom. (That's unusual. Feel free to borrow it, no charge.)
- How about Good Rags to Bad Rags and Back Again?
- Or maybe Rich Rags to Ragged Riches -- a concept that might be interpreted any number of different ways.
- Could you try Dispassionate Riches to Passionate Rags? Sounds like the character might have joined the Peace Corps or some such organization.
- Legendary sword & sorcery author Robert E. Howard built his entire series of Kull the Conqueror stories around Rags to Riches That Aren't All They're Cracked Up To Be, as Kull conquered a kingdom but found kingship to be more frustrating than his old days as a penniless adventurer... and, in some ways, far more dangerous. After a fashion, that's also the same plot used in Harry the Dirty Dog.
When you're struggling for a place to start, consider borrowing a story. You can always pass it on to someone else once you're done with it. ;-)