Write about what you know. So say the writing teachers. I say write about what interests you, what charms you, what makes you care. That way you can tap into more honestly what you 'know.'

I like writing stories. I like fiction. It allows me a lot of room. But it makes you work hard. You can never forget your audience. Locate the story, make your characters readable by having clear motivations and actions and dialogue. Make the action rise from your characters or if you are plot centered, write a hearty fresh plot with lots of turns. Tell a good story. Keep'em listening like the old storytellers did. Who was one of the best old ones? See any film by Cecil B DeMille. Each scene advances the story; each word does the same. He was corny, kitschy but he could tell a good narrative that was clearly motivated, clearly coherent and fun to travel along with. Nothing better.