Because I write books set in the past, something else I have to watch for when I polish a book are anachronisms, words or phrases that are too modern for the time period in which my book is set.
If you've read one of my books, especially those set in medieval times, you'll notice I don't even try to make my characters talk in olde English -- no thees, thous, or mayhaps for me. Oddly enough, considering I'm making these people up, that sort of dialogue makes me too aware that the people are fictional. I do, however, try to avoid anything that sounds too modern, like "no way!" I'll even think twice about something like "Get out of town!" I mean, I could use it, but now it has a slang connotation, so I probably wouldn't.
I have to be careful about time. Until relatively recently, people didn't own watches or even clocks. So I won't have my medieval characters ever tell time in minutes, or say something like "Just a minute!" "Just a moment," yes, but never "just a minute" because they wouldn't be thinking that way. I avoid hours, too. I'll use dawn, dusk, maybe canonical hours, but I usually keep time pretty vague, because for the vast majority of people then, it was pretty vague.
The time period I write in also affects the similes and metaphors I use. I try to make comparisons only to things my characters would see or use in daily life. This can get tricky at times, but I can usually find something.
There are times I wish I could use a modern turn of phrase, and I'm sure there have been places I've slipped up, but I do my best to avoid anything that sounds too modern, even if it's a term or word that really was used at that time. Unless I want to provide a footnote to prove it, I figure if I think it's too modern, so will other people and it'll disrupt their enjoyment of the book, so out it goes.