In many fanfictions, Harry Potter is depicted as learning or already knowing how to dance at the Yule Ball. It depends on the creativity of the author.
Well, a plot twist could be that the dance instructor is actually a disguised Death Eater. They start using the dance class as a cover to pass on secret messages or to plant some sort of dark magic object. Maybe they try to manipulate the students' movements in the dance to form some sort of dark symbol. Another interesting plot twist could be that the magic used in the dance class goes haywire. Instead of normal dance moves, the students start floating uncontrollably or their feet move on their own in a chaotic way, leading to a lot of comical and dangerous situations.
I think Professor Flitwick could be an interesting choice. He is small in stature but big in magic. He could use his charm and levitation spells to create some unique dance effects. For example, he could make the students levitate slightly while dancing to give an ethereal look. His knowledge of charms could also be used to add some fun elements to the dance class, like making the dance floor sparkle or creating musical accompaniment with magic.
One possible fanfic could be about Fleur's grand entrance at the Yule Ball. She might be wearing a stunning, silvery dress that shimmers in the light. The way she glides across the dance floor, attracting the attention of many, including some of the Hogwarts students who are in awe of her Veela charm. She could start the night with a dance partner from Beauxbatons, showing off the different dancing styles from her school.
In some fanfictions, the Yule Ball is a turning point for Harry and Daphne's relationship. For example, Daphne might be a bit of an outcast in her own Slytherin house for being different. When she goes to the ball with Harry, they face a lot of stares. But they don't let it bother them and instead have a great time, chatting about magic, Hogwarts secrets, and their dreams for the future. This could be the start of a beautiful friendship or something more.
There's also a possibility that it's a new character created specifically for this fanfiction. This new character could bring a fresh perspective and allow the author to explore different aspects of Harry's gentlemanly behavior at the Yule Ball.
One possible fanfiction could be that Susan Bones, being a bit shy, is initially hesitant to go to the Yule Ball. But when Harry Potter asks her, she's overjoyed. At the ball, they share a slow dance, and Harry realizes how kind - hearted and intelligent Susan is. They end up spending the whole night chatting and dancing, forming a new friendship that might develop into something more in the future.
There's 'The Yule Ball Encounter' which is a short but sweet fanfiction. It focuses on the moment when Harry and Daphne first see each other at the ball. The author does a great job of capturing their initial reactions and the tension between them. It's a quick read but very engaging.
In a fanfiction, Cho Chang could be the one to take the initiative at the Yule Ball. She might have noticed Harry's nervousness around her and decided to ask him to dance first. As they dance, there could be some flashbacks to their previous encounters, like when they met at the Quidditch match. This could lead to a deeper connection between them during the ball.
In a Yule Ball fanfiction with Pansy Parkinson, she might be secretly nervous. She's used to putting on a tough exterior. But when she enters the ballroom, she's in awe of the beautiful decorations. She spies Neville Longbottom looking a bit lost and decides to approach him, not out of kindness at first but to mock him. However, as they start to talk, she realizes he has a depth she never expected and they end up having a rather interesting conversation throughout the ball.