By Sally Koslow

1. Pick a Human Subject You Find Genuinely Fascinating

Unless they’re crazy-fast, most writers spend at least a year completing a manuscript, and once it’s sold, another year or two may pass until publication. After that, promotion continues for a good, long while. You’ll be channeling your hero and/or heroine for what will feel like forever, so you’d best pick people who are sufficiently complex.

2. Your Character Doesn’t Have to be Wholly Likeable

They do need to be believable and intriguing.

3. Jumpstart Your Research with Biographies

If a biography exists of your subject, lucky you. Begin there. If you’re truly fortunate, there will be more than one biography to inhale. Next, move on to diaries, memoirs, letters, interviews, and related documents.  Your goal is to feel you know your subject at least as well as your best friend. If you’d like your subject as a friend, even better. See Rule #2.

4. Beware of Verbal Anachronisms

I just read an otherwise terrific biographical novel set mostly in the 1950s and 1960s, where the author used the word “alas” at least ten times. I kept wondering if in the next scene I might discover that this mid-century woman wore a whalebone corset and dosed herself with laudanum. Related point: even if “alas” had been an apt word to use, it’s still oddly memorable, and strange to use so often in one book.

5. Avoid Dialogue Tics.

We’ve all learned that conversation shouldn’t be too on the nose and speakers can overlap. In an effort to be period-friendly, however, dialogue shouldn’t mimic every sloppy annoyance of everyday speech. Really. Very. So. Well. Use words such as these sparingly. They are the cayenne pepper of your manuscript

6. Capture Your Subject’s Voice

Read letters and diaries, if any exist. Check for YouTubes—you may actually be able to hear the voice of your subject. It’s essential for conversation and internal dialogue to feel real or your book won’t distinguish itself.

7. Feel Free to Reshape Your Story Line

Even the most interesting person does not lead his or her life in a plot. An author needs to determine not only what events to subtract and re-order in the life of her subject, but what do fictionalize and add. Perhaps your Civil War nurse visits an imaginary hospital in Atlanta, or even a real one in which you can’t that prove she ever set food. Your story may be better for the invention.

8. Enrich Your Book with Historical Details

Consider your book to be the literary equivalent of Colonial Williamsburg. Readers come to any historical novel, biographical or otherwise, partly to learn about a bygone era. Don’t stint on (accurate!) details about clothing, hairdos, food, home design, transportation, gardening, raising children….

9. Beware of Rabbit Holes

In preparation for writing any historical novel, it’s so much fun combing through clippings, tracking down out-of-print books, and watching vintage movies that it’s essential to assert discipline. Otherwise, you may find yourself going down rabbit holes that cause you to either procrastinate or to get so obsessed with a historical footnote that you digress in your writing. Stay on point, people.

10. Stick to Your Era

In a biographical novel it’s essential to color within the lines or your time period’s details. Nothing takes a reader out of story faster than a mistake. You will find yourself researching picky but essential points. Did women wear nylon stockings in 1939? In 1962, could you buy avocados in a Minnesota supermarket? How many stars did the American flag have in 1901?

11. Read Well-Written Novels Within the Genre

You want to be able to identify fine writing and become infected by its virus, so read the best of the best and steer clear of biographical novels with pedestrian writing. Set your barre high.

Sally Koslow is the author of Another Side of Paradise, a biographical novel that explores the little-known love story of F. Scott Fitzgerald and Sheilah Graham, as well as her shocking past. Harper, May 29.