It's awesome that you want to write a story in one of my fandoms! And if you already have a story idea for any of them, I'm sure to love it. But if you'd like to know about some of the things I like, and don't, here you go:
Things That Make Me Happy
I love angsty stories and hurt/comfort. I love banter. I love competent characters behaving competently. I love plotty stories. I love character studies. I love happy endings. I like unhappy endings, if they're of the magnificently tragic variety. I prefer slash, like gen, but am mostly not interested in het. No matter the relationship, emotional intimacy that matters more to me than the physical sort, though I wouldn't turn down some rousing physical intimacy. While I most want to see the characters listed, I am fond of seeing other characters in the fandoms and how they all interact. And I'm not averse to OC's, if they're well drawn and essential to the plot.
Things I Can Do Without
I'd prefer no non-con or rape. I do not get crack!fic, song!fic or the A/B/O trope. I dislike seeing competent characters acting stupidly. I'm iffy on BDSM and most kink. I never used to get Mpreg, but have found that I'm okay with it in Take That if it's Jason having the baby.
And here are my specific requests:
Take That: Mark, Howard, Jason, Robbie
Take That remains the fandom of my heart, and I love them in most of their configurations. TT4 is my preferred era, but I enjoy either version of TT5. I'm not as invested in the TT3 era, except possibly fix-its that get Jason back in the band. I adore wilderness era fic. My favourite pairings are Mark/Robbie and Howard/Jason, though I'm also fond of a Howard/Mark/Jason puppy pile. And if you want to get away from canon, I'd love any AU you can throw at me: steam punk, musketeers, SF AUs in the Kidz spaceship would all be awesome. Wherever and whenever you set the story, I'm awfully fond of hurt/comfort with these boys. I love whumped but strong Mark, strong but vulnerable Howard, smart and vulnerable Jason, and unexpectedly sweet Robbie.
Velvet Goldmine, Arthur Stuart, Slash
For me, the heart of the movie is Arthur Stuart, both the teenage version with his awkward sexual awakening and his tentative bravado, and the disillusioned adult version running into his all-too-human idols. Give me a scene with Arthur and Curt, back in the day. Or a more satisfying reunion with Curt after the movie ends. Or whatever inspires you, really.
Sing Street, Conor, Eamon
I adore this movie. I love everything about it: the '80s vibe and music, the friendship of the characters and they way they work together to become a real band. At the centre of it for me is the friendship between Conor and Eamon. I don't really ship them (I really like Conor and Raphina together), but I love how Conor pulls Eamon into his scheme to start a band, and how Eamon pushes Conor to become a better songwriter. I'd love to see more about how their friendship works as they're setting up the band. Or maybe have Eamon join Conor and Raphina in London and have them crack the English music scene. Or have them struggle in London, but still rely on their friendship. Or skip them forward a few years and see how they're doing and what's happened to their dreams.
Magnificent Seven (1960), Lee
I love all of the seven to various degrees, but Lee is the most intriguing to me. We just get intriguing glimpses of the man he used to be and the one he's become. I'd love to see more background on what happened to him to give him such fear. Or flesh out more of what he went through during the events of the film.
In the end, I hope you write something that gives you joy. That's sure to bring me joy as well.