Are you interested in writing IR?  Interracial romance is a popular (that means selling) subgenre of romance in which the hero and heroine are of different ethnicity. The hero might be African-American, the heroine white...the heroine might be Vietnamese, the hero Native American...there are as many possible combinations as there are perceived races. My New Adult release, A BRAND NEW ADDRESS, is a futuristic IR sweet romantic suspense.

When you write an interracial romance, you're writing first and foremost a romance.  

Step1

Recognize that race or ethnicity is both important to an interracial romance novel...and not important at all. The really important part is the story.

Step2

Create a dynamic conflict around which to center your story. Give your characters good reason to be torn apart...a reason that will keep your readers turning the pages. The conflict needn't center around ethnicity at all.

Step3

Avoid stereotypes in creating your characters. I can't stress this enough, and it applies to all writing, not just writing about different ethnic groups. How to avoid stereotyping your characters? Well...

Step4

Realize that you are writing about an interracial character - i.e., a character who happens to be of a certain ethnicity - and not about an ethnicity cartoon. Just as you are no cartoon image of your own ethnicity, or of your own gender or hair color for that matter, your character is no exaggerated cartoon image, either. Your character's ethnicity is an element of her, but not equivalent to her.

Step5

Assume your character is not made up at all, but a real human being. Your character doesn't spend all day thinking about his race and trying to "act" like he belongs to that race. Your character spends all day wondering if his cute next-door-neighbor knows he's alive.

Step6

Give your character a full, well-rounded background your readers can identify with that goes way beyond the character's ethnicity. For example, if you are writing about a Native American character, don't stop with deciding that the character is a Creek Indian who likes to chat on the Internet, to the consternation of her grandmother.

Instead, have your character live in Mason, Georgia, and have her leave a lucrative career in the textile factory owned by her family in order to go on a stint in the Peace Corps, until she comes down with malaria and she's forced to come back home to recuperate, where, being a high-energy person, she spends all day being pampered by her busybody grandmother and restlessly gets on the Internet, where, in a chat room, she starts chatting with a low-energy man who's Cherokee, of all things...

In other words, put your character into the world your readers know and give her real, well-rounded characteristics. Not a stereotype.

Step7

Do thorough research for your multiracial / interracial romance. Learn about the ethnic background or backgrounds you're writing about. Even if you share your character's background, you may find it useful to learn more by reading and interviewing people. Sometimes the areas we think we know the most about, we learn we don't know well enough to write about well.

Step8

An authentic romance appeals across races, ethnicity, and backgrounds. Assume you have three kinds of readers: readers who are intimately acquainted with the races you're writing about (because they are of that ethnicity, or someone close to them is), readers who have no experience with the races you're writing about, and readers who know a little bit about the races you're writing about.

Your writing must do magical things. Your interracial romance must reach everyone, informing them of what they don't know, without talking down to any of the ones who already know.