NINA: Most of it represents the club, since she was the leader during season 1 to season 3 (or most of season 3, since magnus was the leader during some episodes) she wrote in a diary (in season 1) and has stuffed animals, one of the accessories she uses most is the scarf
DANIEL: Some representing the club, his style of clothing, his bike, the fact that he is intelligent, the subject he excelled in (Chemistry) he is also good at calculations, the color of his iris.
DELIA: she practically only wore heels, most of her clothes were pink, in her room in some episodes it is possible to see bags with expensive brands, she uses a lot of lip gloss, the references on the CDs (detective and club)
FELIX: He loves comics (I'm pretty sure he prefers DC, over marvel In one episode he does makeup similar to the Joker, and I don't remember him making any reference to any Marvel character, as for Magnus, I feel like he prefers Marvel) he loves superman (he has a superman shirt ) He loves horror movies, french fries are one of his favorite foods, He likes games (I can totally imagine him and Magnus playing on the computer or PlayStation) the flower is a reference to the last episode of the first season (the scene with Delia) he likes to dress up as Characters and horror makeup
MAGNUS: He is probably the character who used the computer the most during the 3 seasons, the leather jacket is frequently used by him (he has a brown and black jacket) he only wears polo brand clothes, in the book it is said that he always played golf with his father, I think he is the character who is seen most with flowers (3 times during the shows, mara you are lucky) the poem he wrote for Mara in season 2, and the sword from the movie (my favorite aesthetic of his) He was the club leader during the episodes Daniel was away, and to be honest, the scene with Delia and Felix choosing him over Nina was satisfying (she really irritated me in season 3, like REALLY).
MARA: her eye color + the eye of horús symbol, Mara likes musicals and singing, she loves reading, the statuette she received from a mysterious person (it's not the first time something like this has happened to her, it's said in the book that at the age of 12 she was helped by a mysterious person) one of the hairstyles she uses the most (and my second favorite) the picture of the sand represents the dreams she dreamed (in the sand) and the photo of the crown (she is a decent of the Egyptian royal family) and my second favorite dress of hers (I love the one she wears on her date with Magnus, but I don't have a picture 🥲)
KAYA: He loves sports, he wears jackets like this a lot in the 3rd season, his favorite sport is soccer, on vacation he always goes surfing, he likes to work out, the outfit he wore to go out with Mara, his family comes from Türkiye.
LOTTE: She had a diary (where she wrote a lot about Kaya), she liked skating (for some reason they simply forgot about it after 20 episodes), she is part of the school newspaper along with Luzy, her haircut, she is an intelligent student who gets high grades (she won the award with Daniel, they are probably the two smartest in the house), she loves chemistry (her father is a chemist, I imagine her entering this field after graduating).
LUZY: her hair color, she likes plaid, she has some random scenes kissing people's faces, she has 2 leather jackets (red and black) she wears some sleep shorts with similar things written on them as in the picture, she wears a lot of boots.