Interactive elements
Interacting with stuff in game makes it that much better.
A example of a bad interacting system is pokémon. When you went to read any book there was it would say "Books full of pokémon stuff."
Not just books, but treasure chests, characters and more.
Characters can interact.
Try to keep involving the player in the forwarding of the plot.
"Do you want to go left or right?"
Cause it should be:-
"Do you want to go left or right?"
Not everything has to be interactive but if you don't put some in the player will soon quit bothering to check bookshelfs etc.
Remember:- It's your RPG so just make it so you like it, and therefore other people like-you will also like it.