I think having the right mood to your setting is important and I also think that this can be accomplished through many different ways, including dialogue and such. Here's a very short vocabulary list I've collected, which I really like for medieval and or fantasy themes. Most of it's from George RR Martins A Song of Ice and Fire series. whilst nonce athwart hence erstwhile pray would This is one of the more interesting words actually. If you don't know this already, the word can actually be used in place of "wish." Example: "I wish I knew more vocabulary like this." Or "Would that I knew more vocabulary like this." besides Besides is another one of those words that has another definition that isn't used very often. The world can also mean "as well," or "also." Example: "I'm also leaving." Or "I'm leaving besides." aught naught These words are somewhat archaic but still in use today, albeit rarely. I think they work very nicely sprinkled in in the right spots to give an archaic flair to the work. Of course they'd be out of place if the story wasn't in some sort of historical (realistic or fantasy) setting which would warrant using this type of vocabulary. Yeah that second example I made doesn't quite sound right, but I dunno. Don't feel like wracking my brain to make an excellent sentance with that word for this post right now, lol. Anyways, let me know what you think!