- Inappropriate use of apostrophes (this includes "their" when you mean "they're")
- Using "drabble" to refer to a short fic rather than a piece of exactly 100 words.
- White/bright text on black/dark background.
Also:
Why are (fan)art websites so difficult to navigate?
ataniell93 has some really interesting thoughtful posts on the Wizarding World JKR has created (spoilers through HBP):- the ahistoricity of the 'verse
- psychology in the Wizarding World
- possibilities for queer sexuality given the canon [general terms, not specific 'ships]
For less PostSecret more Nick Bantock fandom postcardage, there is
fandompostcards.snarkhunter talks about the Seven Swan Brothers fairy tale and courage (HP) and writes: "I think I like the idea that you don't have to be a rush-into-battle, Weasley-esque Gryffindor to be brave. You can be like Neville, who's quiet and timid and stands up when it really matters. I like the idea of silent strength, and I think in our rush to find strong feminist heroines, we overlook the quiet ones who hold things together." 