One common theme is family conflict. Since Cedrella is from the Black family which has certain expectations and the Weasleys have their own values, there's often a clash between the two families in the fanfics.
There's a fanfic called 'Cedrella's Choice' which focuses on Cedrella's perspective in her relationship with Septimus. It shows her inner turmoil and how she overcomes family expectations to be with him. It's a really engaging read as it gives a lot of depth to her character.
One great 'septimus heap fanfiction' story could be one that focuses on the further adventures of Septimus in the magical world. It might explore his relationships with his siblings in more depth, like how he and Jenna support each other during a new magical crisis.
Some dedicated book - related forums might also have threads where fans share their 'septimus heap fanfiction'. You can join these forums and start exploring the different stories that other fans have written.
One popular trope is time - travel. For example, Sirius might be sent back in time and meet a younger Ginny. Another is the 'protective Sirius' trope, where he looks out for Ginny in some dangerous situation. Also, the 'mentor - mentee' relationship is quite common, with Sirius guiding Ginny in magic or dealing with the wizarding world's challenges.
Well, a good place to start looking for Ginny Weasley and Sirius Black fanfiction is Tumblr. There are many fanfiction blogs dedicated to the Harry Potter fandom. You might have to dig a bit through the posts, but often they share links to great fanfictions. Also, some Harry Potter - themed Facebook groups might have members sharing their own or favorite fanfictions about these two characters.
It could be one of the Weasleys from the Harry Potter series. Maybe Ron Weasley, who is known for his love of reading (although not specifically mentioned as reading fanfiction in the original books). It could also be a fan - created Weasley character in a fanfiction world who has this rather odd reading habit.
Adventure themes are quite common too. Given the magical world they live in, Acio Weasley might be on a quest, solving mysteries, or fighting against dark forces. This could involve exploring new parts of the wizarding world, using magic in creative ways, and facing dangerous challenges along the way.
A possible plot could be a time - travel story. Ginny accidentally travels back in time and meets a young Sirius Black. They team up to change an event in the past that has far - reaching consequences for the wizarding world in Ginny's time. Or perhaps Sirius, after his death, is able to communicate with Ginny in a way similar to how he did with Harry. He gives her advice on dealing with her relationship problems, like her feelings for Harry and how to handle jealousy among friends.
One plot idea could be that Sirius, who has a connection to Ginny through his friendship with the Weasley family, starts to mentor Ginny in some magical skills. He could share his knowledge of the more dangerous aspects of magic, like dark wizard - fighting techniques, which Ginny is eager to learn. This could lead to a strong bond between them as they train together.