It is inconceivable how little things can make a huge difference when writing in a language that is not your own.
For years now I'm fighting the phrases that come out of me in direct translation, like "she inhaled and exhaled." Only reading copious amounts of books tells me that I can say "she took a breath and let it out" or "she hitched gusts of air" or "she heaved a sigh" or any other variations. In Russian the idioms are often very concrete and have a folk feel to it, from folk tales or fables or parables. Unfortunately, I'm not familiar with the same in American culture so I have to read and read and read. Hope one day I'll be fluent in it and be able to credibly make up my own.