To start a Spirited Away crossover fanfiction, you should first do some research on both Spirited Away and the other work you're crossing it with. If it's a crossover with 'Kiki's Delivery Service', think about the characters' personalities. Kiki is independent and curious, so she might fly into the Spirit World by accident. Chihiro could show her around, and from there, you can explore how their different abilities and outlooks on life interact, and that's how you can start building your story.
First, decide which other world or story you want to cross it with. For example, if it's with 'The Little Mermaid', think about how the underwater world and the Spirit World could connect. Then, consider the characters. Maybe Ariel would be curious about the Spirit World and accidentally end up there, and Chihiro would have to help her get back. Start with a simple scene like that to set the story in motion.
Begin by choosing a crossover concept that really interests you. Let's say it's a crossover with 'Ponyo'. You need to understand the rules and themes of both Spirited Away and Ponyo. Think about how the magic in both stories works. You could start with Chihiro finding Ponyo washed up on the shore near the bathhouse. This unexpected encounter would be a great starting point for the story, and from there, you can build on how their two worlds collide.
One idea could be a crossover with 'Alice in Wonderland'. Chihiro could find herself in Wonderland and have to navigate through the strange rules and characters there, while also using her experiences from the Spirit World. Maybe she'd meet the Cheshire Cat who could be as mischievous as some of the spirits she met in Spirited Away.
Begin by establishing the setting clearly. If it's a Joker crossover with a horror universe, describe how Gotham starts to take on elements of that horror world. Then, introduce the Joker in a way that makes sense in this new context. Maybe he's intrigued by the new horrors or sees an opportunity to create more chaos. You also need to consider the characterizations and how they will interact. The Joker's maniacal nature might clash or blend in unexpected ways with the other characters.
First, decide which universe or character you want to crossover with Morbius. For example, if it's Iron Man, think about how their worlds collide. Maybe Morbius' condition attracts the attention of Stark Industries. Then, create an interesting opening scene. It could be Morbius in a situation that leads him to cross paths with Iron Man, like a strange energy signature that both are investigating.
Begin by choosing the right crossover. Let's say it's Negan and 'Harry Potter'. Think about the rules of the 'Harry Potter' world and how Negan would break or bend them. You can start with Negan somehow getting a letter from Hogwarts (maybe a mistake by the owl post). He shows up at the school, and chaos ensues. Write from his perspective as he encounters magic for the first time. His confusion and his attempt to assert his dominance in this new and strange place would make for an interesting start.
Well, start by creating a scenario that brings the Jashin concept into the other story. For example, if it's a crossover with a game world, think about how Jashin's influence could disrupt the game's balance or create new quests. You could also think about the reactions of the original characters to the Jashin - related elements. Maybe they're horrified, or maybe some are intrigued. Then build your plot around these interactions and reactions.
First, choose the two universes you want to cross over. For example, if it's Miraculous and Naruto. Then, think about how the characters will interact. Maybe Ladybug could learn some ninja skills from Naruto. Start with a simple scenario like an akuma attack in a world where ninjas exist.
First, decide which universe you want to cross Chappie over with. For example, if it's "Terminator", research the lore of that universe. Then, think of a plot hook. Maybe Chappie is mistaken for a Skynet creation in the Terminator world. Next, start writing an introduction that sets up the crossover situation.
First, decide which universe you want to crossover with. Then, think about how the Mandalorian's character traits will interact with the new universe's elements. For example, if it's a crossover with Star Trek, consider how his no - nonsense attitude will mesh with the more diplomatic Starfleet officers.
First, decide which two universes you want to cross over. Then, research both of them thoroughly. Know the rules, the characters, and the settings.
To start a Brave crossover fanfiction, think about the theme you want to explore. If it's a crossover with Beauty and the Beast, you could explore the theme of breaking curses in a new way. Merida could arrive at the Beast's castle and think the curse is some sort of dark magic she can fight. Start with a description of the moment Merida enters the castle, her thoughts and reactions, and then introduce how she'll interact with the Beast and Belle as the story progresses.