First, know the source material well. Understand the characters, the magic system, and the world of Harry Potter. Then, come up with a unique plot. It could be a different take on an existing event in the books or a completely new adventure. Also, stay true to the characters' personalities.
One common trope is the 'alternate universe' where things are drastically different from the original series, like if Voldemort won the war. Another is the 'character redemption' trope, for example, Draco Malfoy getting a chance to be a good guy in a different way. And there's also the 'romantic pairings' trope, like Hermione ending up with someone other than Ron in some fanfictions.
Maybe it's because the fanfiction offers new and exciting storylines and character developments that expand the Harry Potter universe in ways that capture your imagination.
It depends on various factors. The worthiness in a fan fiction often lies in how well the story captures the essence of the Harry Potter universe and how engaging the plot and characters are.
Another reason could be that you're not sure how to find the good ones. With so many fan fictions out there, it's like looking for a needle in a haystack. You might be worried about stumbling upon something that contains inappropriate content or that just doesn't match your taste in the Harry Potter world. And since fan fiction isn't always as polished as the original books, it can make you hesitant to explore it.
One popular platform is Archive of Our Own (AO3). It has a vast collection of Harry Potter fanfics with different genres and themes. Another is FanFiction.net which has been around for a long time and has a large number of Harry Potter fan works as well.
First, give your character a detailed backstory. Think about their family, where they grew up, and what kind of magical upbringing they had. For example, if they're from a pure - blood family, how has that influenced them? Second, give them unique traits. It could be a strange quirk like being able to talk to portraits in a special way. And finally, make sure their actions and decisions are in line with their character. If they're a shy person, they probably won't be the first to volunteer for a dangerous mission.
To develop the characters, start with their backstories. For the brother character, think about his childhood, his relationship with his parents, and how it differed from Harry's. Give him unique traits, like being more interested in potions than in Defense Against the Dark Arts. Also, show how he reacts to different situations. If he's faced with a Dementor, does he freeze or fight back? His reactions will shape his character.
Well, you could write a fanfiction where Voldemort is reborn not as a full - blown villain but as a conflicted character. He might start to question his past actions and try to make amends in a very strange way. Harry could be the one who has to guide him through this transformation, and there would be a lot of tension between the two. Also, what if Voldemort was actually an experiment gone wrong by some ancient wizards, and Harry discovers this truth and has to decide whether to expose it or keep it hidden for the sake of the wizarding world's stability. And then there's the idea of Voldemort's diary having a different kind of magic that instead of just influencing Ginny, it starts to influence Harry in a positive way, making him see Voldemort as a potential ally against a new, emerging dark force.
One plotline could be that the'slave' character has a hidden power that only Harry Potter can unlock. As they interact more, the slave helps Harry in his fight against the dark forces in ways no one expected. For example, the slave might have the ability to sense danger from dark magic long before it arrives, and this warns Harry and his friends in time to prepare for battles.