I absolutely love writing collaborative fiction, so for quite a while now, the idea of participating in a fiction based fandom (we won't talk about what fandom it is) has appealed to me. It's probably more surprising that I've never been part of one, because no lie, I'm an avid RPer. I've been a little nervous to just jump in, because I have too much respect for fandoms to barge in and muck up a storyline. In preparation, I've been reading up on some of the best tips for participating in a fiction based fandom so you can have fun while still being respectful and fitting in.
Joining a fiction based fandom is a lot like participating in an original RP storyline, but there are some very important differences. Notably, you're dealing with an established cast of characters. You need to know the canon: the ins and outs of those characters, their personalities, their behavioral patterns, their histories, their dreams; the full spread of the universe; and what would be in-character for any given person. You're encouraged to have original ideas, but you'll need to respect your fandom's rules about accepted canon and what changes are accepted or frowned upon.
Okay, so this isn't exactly a requirement. You can write all the fan fiction you like no matter what your skill. However, if you're a good writer with a grasp of grammar and punctuation, an interesting tone, and persuasive voice, more people will read your stories – and you're more likely to score some writing partners!
As briefly mentioned, you need to know the rules of whatever fandom you choose. Bust in doing a bunch of things the fandom doesn't accept and you'll get kicked out in a trice. When you're joining an established forum, especially, you need to be respectful.
The best way to engage your readers is to have excellent ideas. Think of things that haven't been done to death, in the world of your fandom and by other writers. Get inspired by your fellow participants, but don't copy any ideas. Bring your own thoughts to the table, and then collaborate with someone who inspires you!
Ah, the One True Pairing. Who do you ship? Are you a Drarry? Do you ship Dexter and Deb? There are popular pairings and not-so-popular pairings in every fandom, but ship what moves you. If you can write good stories for your OTP, you can entertain even the non-believers.
Fandoms have their own lexicon, can you tell? And a Mary Sue (or a Marty Stu) is worse than a scarlet letter in the world of fan fiction. Mary Sues are idealized, perfect heroines with too many attributes and no weaknesses. They usually have long, flowing hair, big breasts, fierce independence, tender vulnerability, strong spines, and the innate ability to cry crystalline tears when things aren't going their way. They typically represent an author's attempt to put herself in a particular fandom, usually romantically paired with her favorite character. Some people accuse Bella Swan of being a Mary Sue, just to put it in perspective. Marty Stus are, clearly, idealized male characters. No one will like you if you insert a Mary Sue into every story.
If you have hardcore love for a particular character or pairing, you have to understand that you're not the only one. Don't get possessive over characters, or angry at other writers if they pair your favorite character with someone of whom you don't approve. Remember, this is all about collaboration – just enjoy the variety!
I think fiction based fandoms are awesome; in lurking around my particular fandom and reading the stories, I've discovered so many wonderful writers who tell truly interesting, intricate stories. Have you ever joined a fandom or RPed a little? If you want to share your OTP, maybe I'll share mine!