One idea could be that Hermione discovers belly dancing as a form of stress relief during her hectic Hogwarts years. She starts learning it secretly in an abandoned classroom and gradually becomes really good at it. Her friends notice a change in her confidence but don't know why until they accidentally discover her dancing.
You could start by looking on fanfiction websites like Archive of Our Own (AO3). There are often a variety of stories related to different concepts, and it's likely you'll find some about Hermione and belly dancing there. Just use the search function and type in relevant keywords.
One possible plot could be that Oliver, being the Quidditch enthusiast, asks Hermione for help with strategizing for an important match. Hermione uses her intelligence and knowledge of spells to come up with unique plays. Along the way, they develop a mutual respect and friendship.
One possible plot could be that there is a competition in the wizarding world to create the best cross - fictional costume. Hermione decides to go all out with a Princess Leia look. As she prepares for the competition, she starts to study more about Princess Leia's character and finds inspiration in her leadership and determination. This makes Hermione more confident in herself and she not only wins the competition but also uses what she's learned to stand up to some bullies in the wizarding world. The fanfic could focus on her personal growth through this experience of dressing as Leia.
Well, one possibility is that Hermione uses her intelligence, like she did at Hogwarts, but in the world of hitman. Maybe she'd use spells in a creative way to take out targets without being detected. For example, she could use the invisibility spell to get close to her mark.
She might be a maid at a magical inn. Hermione could encounter all sorts of strange wizards and witches as she cleans their rooms. She could stumble upon a mysterious object left behind by a guest and then begin a quest to figure out what it is and where it belongs, using her vast knowledge of magic.
The plot could be that a mysterious collar is found in the Forbidden Forest. Hermione, being curious, examines it and accidentally activates it. The collar then starts to affect her magic in strange ways. Harry has to help her figure out how to remove it while also dealing with threats from dark forces who are interested in the collar's power.
Well, one possibility could be that Hermione discovers she has some connection to the Heir Stone family. Maybe she's a long - lost heir. In the fanfic, she could be on a journey to uncover the secrets of this family while also dealing with her normal Hogwarts life. For example, she might find ancient spells or artifacts related to the family that help her in her studies or in battles against the dark forces.
One possible plot could be that Hermione is in a magically - induced sleep and she's placed in a strait jacket as a safety measure by some over - cautious healers in St. Mungo's. And then the story could be about her waking up and using her intelligence to figure out how to get out of it in a non - violent and smart way.
One idea could be that during detention, Hermione discovers a hidden magical artifact in the classroom. This leads to an adventure where she has to figure out its purpose and keep it safe from those who might misuse it.
There could be a belly dance fanfic set in a fantasy world. In this world, belly dance is a form of magic. The main character, a belly dancer, has to use her dance to defeat an evil sorcerer who is trying to steal the magic of dance from all the dancers. She teams up with other dancers from different regions, and together they create a powerful dance that overcomes the sorcerer.