Curses
Cursing in writing has evolved as my writing and I have evolved.
When I first started seriously writing, I was twelve, and so saying "crap" or "freaking" was basically the extent of my cursing in my first novel.
Once I hit high school, however, I realized that my first novel, started at 12 and finished at 13 (65,000 words, so not too short even) I had been writing with my parents looming over me, and my ultra-Baptist friend aiding my brainstorming, and so some more realistic sides of myself and my characters, I was afraid to portray. And that- as well as unexperienced writer errors- majorly took away from the realistic nature of the book and made it seem like a childish, clean fantasy when really it was a dark story of struggle and the fight for love and humanity, fought by mid to upper teens, not children who were afraid to say "ass" in front of mommy.
And so then, I started writing for me. I started writing the way I would live, and the way real people would speak and live, and now, as a young but legal adult and writing New Adult novels, I'm not afriad to drop words like "fuck" and "bitch" and "cheeky little twat waffle." I grew up, and so did my writing, and cursing came with that. I don't think there's a single thing wrong with cursing in writing, where it makes sense. If it contributes to the piece to drop an F-bomb twenty-five times, then by all means, go for it. Write that shit, dammit, or no one else will!
Curses are words too, so why limit ourselves as writers to only a select group of words, when we have the entire world of communication at our disposal?