If you run games then do listen to these two podcasts:
- Ken Hite on Masterplan
talking about his Day After Ragnarok setting. The start is more directly on Ken's publication but afterwards is a lesson in how to create a setting by focussing on the theme and murdering your darlings.
-Robin Laws on Gamer's Haven
talking about Hamlet's Hit Points, his examination of storytelling beats in films as an aide to supporting narratives in roleplaying games.
Either will give you much food for thought.