For our purposes in talking about framing stories, we will define the story being framed as the plotlines explored directly by the narrative. To take a well-known example, look at Harry Potter. The plotlines of the character arcs, and combatting Voldemort, are the core story. A framing story could be if there were a line at the beginning or end of the books saying "based upon the diaries of Harry Potter, Wizard." Which takes us conveniently to the next set of definitions we need to supply.
I don't actually know how much this post will help you in ridding your works of pesky anachronisms, but the title just seemed to clever to resist. If you're not already familiar, an anachronism is a literary, spatial or temporal (usually temporal) transplant. A detail, a phrase, an expression, a device, or really anything else could be an anachronism; most commonly these are stock expressions or devices of our own time that we accidentally put into our works. Nor are they unique to literature, as there are plenty of examples in movies and other media. For instance, perhaps a period movie might show cars from a later model year driving around in the background. Or my personal favorite, when an author or screenwriter has archers "fire" their arrows, an expression which could not predate the advent of firearms. This last one even made its way into The Lord of the Rings movies (notably during the battle at Helm's Deep).
In my most recent reread of The Lord of the Rings, I expressed that there is a certain mythical quality to the story and its manner of telling, and that is even more so present in The Silmarillion, which makes sense: according to the letter of Tolkien's included with the text, Middle Earth was intended to be a sort of original mythology, evolved from the languages he had invented.
I've said it in every other post about these books so far, but I will say it again: you should read The Lord of the Rings. If you haven't read them, then a) I'm very sorry for the sad life you have heretofore lived, and b) you should read them immediately. If you have read them, then you should reread them. These are the kinds of books that spoil you for everything else that isn't nearly half as good as they are.
At the end of The Two Towers, if you're not familiar with the plot already, you'd probably believe that this story is not going to end well. Of course, the biggest spoiler of this book is its own title, which Tolkien did not pick. His original choice for the title of the third part of The Lord of the Rings was The War of the Ring, but he was persuaded to change it to the more positive, and arguably more descriptive, The Return of the King. Knowing this history, I'm not entirely certain which title I prefer. However, I am entirely certain that I enjoyed this part of the story just as much as the others.
There is a fair consensus amongst those who come to consensuses about such matters that Tolkien wrote The Lord of the Rings primarily as a way of exploring Middle Earth - that is, this is what is known as a milieu story, in which the setting, the world, drive much of the plot. In The Two Towers this is on fine display again. One of the more interesting things to do with a copy of The Lord of the Rings is to sit down and look at just how much ground is covered by the various journeys; you then realize just how large a world Middle Earth is, and how small a section is explored in these tales. The distance covered by Frodo and Sam through such great peril and difficulty in the entirety of their chapters in The Two Towers is essentially a tiny corner on the map.
As I said in my review of The Hobbit, during this reread I was surprised by how light that novel is; I suspect that my memory of its tone from my last reading was affected by my intermediate viewing of the movies. Or, perhaps I was merely linking it with the core Lord of the Rings books, which very quickly take on a markedly different tone from their prequel (and yes, I know that technically there is just one "book," which was split into three parts for the convenience of readers and publishers). The implications of a darker turn are heavy throughout even the early chapters of The Fellowship of the Ring, but are pivotally confirmed with the events of the chapter A Knife in the Dark.
I remember having several English teachers, especially early in my schooling, who spent a great deal of time talking about how important a good opening line is. As they likely did for many of you, they called this opening line a “hook,” and explained how the entire fate of the universe, or at least my essay, rests on having a “hook,” a first line that will draw readers in and make them desperately excited to learn more about what I have to say on such fascinating topics as Lyme’s disease, Abraham Lincoln’s boyhood home, or the intelligence of dolphins.
Finally, I am undertaking my re-read of The Hobbit and The Lord of the Rings. There are certain books that are always worth re-reading, no matter how many times I may have read them before, and these most definitely make that list. Since this is the first time I'm re-reading them since I started posting reviews here on the site, I think it is only appropriate that I go ahead and review them here. In the case of The Lord of the Rings, I usually try to do a re-read every four or five years, since the first time I read them back in third grade. We'll see if I decide to re-read and post a review for The Silmarillion, too.
I have made it a policy here on the site not to post reviews for books that I read in the past. That is, while there are many books that I read before starting this site and before starting weekly reviews on the site, I only intend to post reviews for those books if I actually sit down and re-read them. In some cases, like for books that are a part of ongoing series, that means that reviews for the older books will likely be posted eventually as I re-read to get caught up for a new release (like we did for the Stormlight Archive books). There are a lot of books that I would like to add to the review collection that I've already read, but with a reading list as long as mine is, it is increasingly challenging to justify spending too much of my time re-reading books.