Well, it could be that Harry and Ginny use their own experiences with dark creatures and magic to create really interesting and hands - on lessons. For example, Harry might demonstrate how to fend off a Dementor using a Patronus charm, while Ginny could show how to deal with a Boggart in a practical way.
In the fanfiction, they might introduce new and unique defense techniques. Since they have faced some of the darkest wizards and creatures, they could have developed their own ways of defense. Maybe they teach a new form of Occlumency that combines both of their methods, and the story could be about how the students adapt to this new teaching style.
Another possibility is a new dark wizard or witch who emerges and wants to prove themselves by taking on Harry and Ginny. This antagonist could be jealous of their fame and power and decides to target their DADA class to show that they are not as great as everyone thinks. They could try to undermine the students' confidence in Harry and Ginny's teaching.
Well, perhaps in this fanfiction, Harry and Ginny teach at Hogwarts during a time of new threats. They use their unique skills to train students in a more practical way. Ginny, as a Quidditch star, could revolutionize the Quidditch teaching. Harry, on the other hand, might introduce new defensive spells that he learned from his adventures. And they could also have to deal with the politics within Hogwarts, like some teachers being jealous of their popularity among students.
The plot might involve Harry and Ginny sharing stories of their battles against Voldemort with the Marauders. In the process of teaching, they could also learn from the Marauders' own pranks and their way of dealing with difficult situations at Hogwarts. This exchange of experiences could lead to new friendships and a better understanding between the two groups.
In a 'harry is a dada assistant fanfiction', the plot could start with Harry being curious about a strange object that turns out to be a device with Dada Assistant on it. As he starts interacting with Dada Assistant, he realizes that it can help him in his studies at Hogwarts in unexpected ways. But then, there could be a conflict when some of the Hogwarts professors think that this new 'technology' is against the rules of magic. Harry then has to find a way to prove that Dada Assistant can be a useful tool in the wizarding world and not a threat.
In this fanfiction's afterlife, Harry and Ginny might be in a place where time has no meaning. They could be constantly surrounded by a warm, golden light that represents all the love and positive energy they've created during their lives. They start to discover hidden powers within themselves that allow them to shape the afterlife realm. For example, they might create beautiful gardens filled with magical plants that only exist in their memories from Hogwarts. Their relationship becomes even deeper as they work together to make this afterlife place a haven for other souls.
Maybe in this fanfiction, they are at the lake to practice some magic. Ginny could be showing Harry a special spell she learned, and they end up having a little magical adventure right there by the lake. For example, they might accidentally summon some friendly magical creatures from the water.
Well, it could be about a friendly duel for practice. Maybe they are trying out new spells they've learned at Hogwarts. Harry might use his signature spells like Expelliarmus, while Ginny shows off some of the more advanced spells she's picked up from the D.A.
Well, one idea for the 'Harry and Ginny elope fanfiction' plot is that Ginny convinces Harry to elope. She's always been a bit of a rebel. They might leave Hogwarts in the middle of the night using magic to cover their tracks. They could end up in a magical forest where they discover new magical creatures and have adventures together, all while keeping their elopement a secret from their families.
One possible plot could be that Harry and Ginny are wrongly accused and sent to Azkaban. They then have to find a way to prove their innocence while dealing with the dark and dreary environment of the prison. They might discover a conspiracy within Azkaban that is related to the real culprits they are being framed for.
Well, in some fanfictions, Harry might draw on his own experiences facing dark magic. He could use his adventures with Voldemort as real - life examples to make the lessons more vivid. For instance, when teaching about defensive spells against the Imperius Curse, he could talk about how he resisted it in his encounters.