WRITE WHAT YOU KNOW -- A SHORT EXAMPLE

The advice you hear out there as a beginning author is, "write what you know," as well as, "write something you'd like to read yourself." That advice is sometimes easier said than done, especially if both statements are in opposition to each other. For example, I may like reading about a Chinese family and how they survive under Communist rule, but I wouldn't write one since I'm not familiar with anything about the theme or the culture.
When I first got the idea to write The Coin, the first thing that came to mind was: What would happen to a woman like myself (who had found many coins on the mountain, by the way), if one particular coin would expose a very nasty man's secret? That simple question spawned the write what you know concept. My main character became Gabriela Martinez, Cuban-American woman living in Europe (like myself), familiar with the effects of exile and the vagaries of life (myself again), at the cusp of achieving the recognition for her career (my desire to achieve that as a writer), and what would happen if the person who is sent to protect you puts you in emotional peril (not me, but a great wrench thrown into the conflict). It was something I could tackle and explore. The type of novel I love to read, where a normal person is thrown into untenable circumstances, and whose inner strength helps them triumph and overcome.
But, how to make sure the bad and good guys know about her finding that coin? Well, the write what you know came to the rescue again. As every Cuban-born person knows, we love our bracelets, and every woman has one with a ton of big and heavy (and I mean big and heavy) gold charms. Charms galore. Some have Christian medal charms, ALL have the azabache - jet stone (a hard black semiprecious variety of lignite) - to ward the evil eye, and, you guessed it...coins! Problem solved. My character would place the coin on the bracelet she always wore and, Bingo, the inciting incident is off and running.

Here is a picture of my mother's bracelet (left), and my ex brother-in-law's mother's bracelet (right) and the excerpt from the novel where the conflict wheels are set in motion. Enjoy.

FROM THE COIN:
With past events still rancorously boiling in his mind, David diligently cleaned the coin, prepared the ancient camera equipment, and took close-ups of both sides of the small coin. Why didn't the old man get one of those instant cameras that cluttered the market nowadays? It was more modern, practical, and wouldn't keep wasting his time. But like everything else that pertained to these coins, David knew it was futile to complain.
As night closed in, David set about finishing his other tasks as quickly as possible. Once finished, he placed the photo roll inside a padded, stamped envelope, and meticulously closed the jewelry shop. On his way home, he dropped it off at La Poste and forgot about it.
Little did he know a discreet worldwide alert would be issued barely two weeks later.

My ex brother-in-law's mother's bracelet. He graciously let me borrow it for a signing event.

My mother's bracelet.