In The Letters of J.R.R. Tolkien, Tolkien wrote, “The invention of languages is the foundation. The stories were made rather to provide a world for the languages than the reverse. To me a name comes first and the story follows.”
If you’re thinking of creating a Lord of the Rings Halloween costume and want to make it as authentic as possible, or if you love invented languages, check out Tolkien speaking in Elvish and then peruse the languages he created.