As a writer of primarily science fiction, I've often struggled with finding a happy medium between making the prose/dialogue relatable for readers and avoiding using too many "Earth words" as I've come to call them. On a couple of occasions, I've had readers mention that the use of idioms, etc. (especially American ones) seemed unrealistic for the alien culture featured in the story.
A couple of "Earth words" I've gotten hung up on are related to characters' hairstyles: ponytail and mohawk. Obviously the latter is a Native American word, and the former looks like a horse's tail. But in a fictional universe where Earth doesn't even exist (and therefore the Earth-based origins of these words doesn't exist) would they seem totally out of place? Or if you were a reader, would you even notice them because they're so commonplace?