DON'T write Bella or Anastasia from Twilight and Fifty Shades of whatever. Mary Sue is a stand in character for the reader, giving them a way to live out the fantasy you are writing. Sometimes this is exactly what people WANT to read. There's a bland character on page, but the reader can imagine other stuff and become the character. Especially with the first person POV. Second and third person POV is harder to do this in. No complicated long names. I promise, that's a dead give away. While men can fall in love with her. Don't make it about her Beauty????? there's an anime called Ouran High School Host Club, and it's a reverse Harem anime. Basically, this girl goes to a rich kids school, and she breaks a vase and is in debt to the Host Club who doesn't know she's a girl. Anyway, they dress her up and over the anime she makes friends with girls and guys. But they EACH have a different reason. Now. This would be generic mary sue type of stuff if it isn't for the MC's characteristics. Which is she doesn't like BS, she tells it how it is and while she is kind. She genuinely wants to help people. I say, watch a few episodes. it shows how a Mary Sue situation can be rather different and stuff. at least. it's better than some western media. lol.
This is an interesting show about the Mary Sue, and how it's not really about the superficial elements like appearance or skill. It's about the world bending around her:
That was very interesting, and food for thought. I have to say, reading about Mary-Sues can be a lot of fun and, let's face it, we've all been there and we should applaud their (usually young) writer for having the passion and creativity to pen something and the confidence to share it with the world, even if they will look back on it in five years' time and want to vanish into a hole. (Totally not speaking from experience there.) Thanks for sharing, I think I'll check her out.