First, find some interesting prompts. You can look for them on fanfic writing forums or websites dedicated to fanfic. Then, choose the fandom you want to write about. After that, start brainstorming how the prompt can fit into the world and characters of that fandom. For example, if the prompt is 'a character discovers a hidden power' and your fandom is Harry Potter, think about which character could discover this power and how it would change the story.
One creative prompt could be to imagine you are a peasant during the French Revolution. Describe your daily life, the fear of the guillotine, and how the political unrest affects you. This allows for a vivid exploration of a historical event from an ordinary person's perspective.
One great free write prompt for fiction could be 'A character discovers a mysterious door in an old attic.' This immediately sets a scene full of potential. The character could be anyone - a curious child, an old homeowner, or a nosy neighbor. And the door? It could lead to a magical world, a time - locked room filled with secrets from the past, or a portal to another dimension. It gives the writer a lot to work with in terms of creating a story.
Some of the best story prompts for writing fiction are those that can create immediate conflict. For example, 'Two people who must share a secret but don't trust each other'. This can lead to a lot of tension and drama in the story. 'A character trapped in a place they can't escape' is also a strong prompt. It forces the writer to think about how the character will deal with the situation, what their internal thoughts are, and how they might attempt to break free. And prompts that deal with moral dilemmas, like 'A decision between saving a loved one or doing the right thing for the many', can result in very thought - provoking fiction.
One prompt could be 'Describe a character who has a unique quirk and build a short story around how this quirk affects their daily life.' For example, a character who can't stand the color yellow. Every time they see it, they freeze. This could lead to all sorts of comical or tense situations in a story.
One great love prompt for fanfic could be 'Two characters from different worlds fall in love during a journey together.' This allows for a lot of exploration of their differences and how love can bridge those gaps. For example, in a fantasy fanfic, a human and an elf might meet while on a quest to save their respective lands. Their love story can then be intertwined with the challenges of the quest and the cultural differences between their races.
A spooky prompt could be 'A haunted forest'. You start by describing the forest as dark and foreboding. The trees are gnarled and seem to reach out like twisted arms. There are strange noises like whispers in the wind. A character enters the forest, and as they do, they feel a sense of dread. Maybe they see a figure in the distance that disappears when they look closer. This can lead to a story about the character trying to find their way out while being haunted by the unknown entities in the forest.