I found these interesting and thought you might, also.
If you’re in the mood for a list, consider “The 5 Best Punctuation Marks in Literature.” It’s easy to underestimate the work punctuation can do.
We tend to obsess over first sentences. Have writers always done this? Look at a bit of history: “In Search of the Novel’s First Sentence.”
How characters react to each other can characterize, but those reactions can be complex. Writing them well might be the “One Weird Trick That Makes a Novel Additive.”