Found footage, letters to a loved one, and many more are discussed in this episode about this classical but nontraditional method of storytelling.
Here we discuss different ways storywriters can use “found footage” and the “epistolary” (letter, journal) formats. It’s hard to describe, but novels, film, games—one innovative technique is to use environmental materials (like invented newspaper excerpts, letters, tapes) to give an interactive experience within a story. We’ll go into several examples of “found footage” stories which might give you some ideas for new story forms. (That’s funny, because the epistolary is one of the oldest novel forms, dating back to the 17th Century!)
Examples: Robinson Crusoe (journal)
Bridget Jones's Diary
Blair Witch Project
Gone Home
Myst