Fandom is a giant karaoke bar.
Fandom is a giant karaoke bar where there are good singers and there are bad singers, but everybody's there to listen to singing because we enjoy it.
Fandom is a giant karaoke bar, and maybe you want to get better at singing and solicit advice. "Was I off key? How do I keep my voice from giving out?" And you maybe improve or maybe not, but you try, and trying's part of the fun.
Fandom is a giant karaoke bar, and maybe you don't want to become a world class singer, you just want to have a little fun with friends, get a good laugh out of the songs you choose. Maybe your singing sucks and maybe you'll never become a professional singer, but that's okay, you're having a good time.
Fandom is a giant karaoke bar, and maybe you're one of the best singers around, and maybe people clap harder when you step on stage, but that's just normal. People like talent, most of the time, and they like recognizing you for it.
Fandom is a giant karaoke bar, and maybe you're out in the audience and a really shitty singer steps up to the microphone, and maybe you're laughing with friends behind your hands, but generally it's not cool to start booing, because hey, maybe they're horrible, but they're out there to have fun, and it's not really your job to harsh their mellow, you know?
Fandom is a giant karaoke bar, and no one likes it when somebody grabs the mike and yells that you're all singing off key and goddammit, you all need voice lessons, because seriously, you're in a fucking karaoke bar.
If it gets too bad, there's always the bathroom.
Also, in the interest of showing what I consider helpful advice (and also, create a central resource for myself), here is a few things that were helpful to me:
synecdochic's various posts of writing meta - These cover a wide range of topics, from methods of characterization to the beta process, and even if you don't agree with her, it will make you think about your writing in new ways. Which is good.
resonant8's How To Write A Sex Scene - Oh, look! And she doesn't mention Minotaur once! This advice is not so much about the technical details, as it is about the process and the way you approach one, which, ultimately, I find more helpful.
astolat's pretty general advice on writing. - Also, not so much about the technical stuff, but more about the process.