When readers first discover the existence of fanfiction, their first reaction is often, "You can't be serious!" That's pretty understandable--what kind of people spend their time reading and writing about other writers' characters? Well, to tell the truth, slightly obsessed ones. We know it; we don't apologize. And we understand-that was probably our first reaction, too. It's often followed by the second reaction, some variation on, "This is amazing!" or "Why didn't anyone tell me this was out there?"
Fanfiction is the ultimate tribute to our favorite writers and their compelling characters. It's not the provenance of 13-year-old girls with "I Heart Edward" drawn in glitter pen on their notebooks (though there are certainly excellent teenage writers in every fandom). It's a creative outlet for people of every economic and educational level; the Twilight, The Office, and Harry Potter fandoms, where I hang out, has lawyers, doctors, professors, and other professionals with PhD's, Masters' degrees, and other significant accomplishments.
So, if you daydream about Edward, Harry, Clark, Wolverine, Mr. Darcy, or any of the hundreds of characters that capture our imagination, why not try writing your own fanfiction?
Here are some tips for getting started.
Know your canon! Canon is the official story, the book, TV show or movie created by the writers. The whole point of writing fanfiction is to spend more time in this world, with these people. Don't break the rules of the world that the author set up. For one thing, it will be extremely distracting to your reader to be constantly thinking, "But you can't Apparate inside Hogwarts!" or "But Jasper's older than Edward!" There are ways to break canon, and we'll get to those, but be familiar with the world you want to write in.
Start by asking "what if?" This is an easy way to begin any story, including fanfiction. What if Charlie was changed into a vampire? What if Harry and Hermione made out? What if Charlotte died and Mary Bennet went to be Mr. Collins' housekeeper? What would vampires do in the event of a biological weapons attack? Go crazy with it-you don't have to write every crazy thought you have.
Don't be afraid of hard topics. The fanfiction world is largely made of adults, and has a sophisticated ratings system in place. So don't be afraid to ask, "How would Edward react if Bella got raped?" "How would Harry and Ginny deal with infertility?" or any other sensitive topic that real life presents.
Don't forget warnings. If you choose to write on a sensitive topics, make sure your story summary warns your readers that those topics are included. Some readers prefer to avoid certain stories and should have the chance to do so.
Find a beta. This is an absolute. A beta is basically a proofreader or editor. This is the person who will catch the mistakes you're too close to see. Every fanfiction writer, even those who are professional writers or English professors, should have a beta. You may be a brilliant writer, but something is going to slip by you. Always have a second set of eyes look things over for you. For example, I'm a professional writer, college professor, and have a doctorate, but I still have at least 2 betas look over everything I write.
Never apologize. Don't write, "I'm sorry if this isn't very good," or "This is my first fanfiction, go easy on me," in your summaries or chapter notes. If you believe in your story, if you've put the work in, the story will speak for itself. If you have something to apologize for, it's not ready to post.
Give a little, get a little. Reviews are money, chocolate, and oxygen for fanfiction writers. One way to get some is to give some. If someone takes the time and trouble to review your story, why not go find one of theirs and offer one to them?
Follow the rules. Different fanfiction sites have different rules, so you really do need to skim the submission guidelines before submitting a story. It's easier and less embarrassing than getting your story pulled off for noncompliance. And there is ALWAYS a site that will take your story, no matter what it is.
Alternate Universe (AU). This is where you get to break the rules. You can label a story AU when you are deliberately departing from canon. If Sirius didn't go to Azkaban, or Esme's baby didn't die, or Mr. Darcy fell in love with Jane instead of Elizabeth, for example. But even if your story's AU, you still have to stick to the rules of the world as much as possible. In your summary, make sure you indicate what the AU elements are: "AU after Book 6," "Does not include information in Breaking Dawn."
Those are a few things to know as you start to spend time in your imagination in the world of your favorite characters. After a chapter or two, it'll come easy, and you'll feel like a pro.