Week 2: Conflict
Character development is at the heart of any novel, but it's crucial when you're writing fanfiction. Your readers are already intimately familiar with your characters. Does the way you portray them match up with the version they have in their heads?
First, a caveat. No two people will see a character in exactly the same light. Part of your job as a writer is to believe enough in your version of the character that the reader will accept it, even if it's not the way they saw them before. Your words must carry enough authority that they will lay aside their own thoughts and opinions long enough to enjoy your story. Perhaps in the process they might even change their minds.
That aside, there are certain things we know about Austen's characters. If you stray too far from accepted reality--say, if Mr. Darcy is suddenly acting more like Henry Crawford than himself--you will lose the reader.
His Good Opinion was enjoyable to write largely because I simply immersed myself in Darcy's character. A version of him took up residence in my head--I call him the Darcy in my Head. DIMH gave me flawless advice about what he would do next, and what he was actually thinking at various points in the story. Examining the slow process of his transformation into a man "capable of pleasing a woman worthy of being pleased" both exasperated and delighted me.
Colonel Fiztwilliam is very different from his cousin. In my story, he is the youngest of three siblings. The nagging of his older brother and sister and the constant fretting and worrying of his mother are part of what propelled him into military service. He is confident and sure of himself, and not unaware of the effect his uniform has on the female sex.
Which characters are you focusing on? Do you have a solid picture in your mind of who they are at the beginning of the novel?