It's also possible that they meet at a Weasley family gathering that Harry attends. Ginny, being the youngest Weasley, is a bit shy at first but then Harry says something funny or kind, and that starts their interaction.
One possible scenario could be that Ginny meets an old acquaintance who has changed a great deal and she starts to have feelings for this person while still being with Harry. Maybe they share a common interest that she feels Harry doesn't understand. However, this goes against Ginny's strong character in the original series, so it's a very different take in fanfiction.
In some versions, it could be that Harry has to die to break a dark curse placed on Ginny. He discovers that his life is the key to saving her and willingly gives it up. He might have a premonition about Ginny's fate and decides that his death is the only way to change it. He then confronts the source of the curse and allows it to take his life instead of Ginny's.
They could have a slow dance under a starry sky charm created just for the ball. Harry would hold Ginny close and they'd look into each other's eyes, lost in the moment.
Maybe they go to a wizarding cottage in the countryside. They explore the nearby magical forests together, discover new magical creatures, and Ginny could teach Harry some new Quidditch tricks in the large open fields around the cottage. And of course, they have cozy evenings inside, cooking together and snuggling up by the fireplace.
In some fanfictions, Harry and Ginny might fight side by side, using their respective magical skills. Ginny could be shown as a fierce fighter, using her Bat - Bogey Hex to great effect against the enemies, while Harry uses his Patronus to protect them from Dementors if any are present during the battle.
One possible scenario could be Ginny trying to control who Harry spends time with. For example, she might not like him being around Hermione so much because she's jealous. Another could be her trying to control Harry's actions in the wizarding world, like which quests or missions he undertakes. Maybe she thinks some are too dangerous and tries to stop him forcefully.
In some fanfictions, they might go on adventures together. Exploring the wizarding world more fully, perhaps seeking out new magical creatures or ancient magic. They have a thirst for discovery after the chaos of the war. Harry's knowledge and Ginny's courage would make them a great team on these excursions.
They might get married and start a family right away. In fanfiction, it's common to see them settling down and having kids, living a peaceful life after all the chaos of the battle.
One possible scenario could be that they meet in the ruins of Hogwarts. The war has just ended, and there's a sense of relief and newfound hope. Harry spots Ginny among the crowd of survivors. Their eyes meet, and without a word, they rush into each other's arms and share a passionate kiss. It's a moment of pure emotion, a celebration of their survival and their love that endured through the dark times of the war.
Another possibility is that they would take a stroll in the moonlight around their new home. They would hold hands and reminisce about their adventures at Hogwarts. Harry might tell Ginny how much he loves her all over again, and Ginny would respond with sweet kisses, and then they would go back inside to have a warm drink and cuddle by the fireplace.