If you really want to improve your stories/plots/conventions/archetypes I can't suggest enough that you read Joseph Campbell's, The Hero with a Thousand Faces (
http://www.amazon.com/exec/obidos/AS...237080-7995312)
A must have book which utilizes this to great effect is Christopher Voglers', The Writer's Journey: Mythic Structure for Writers (and the classic Jungian archetypes) is (
http://www.amazon.com/exec/obidos/tg...glance&s=books). It deals more with screenplays, but the premise is the same. In effect what you're producing is a pageant anyway.
You should find these two books will help your writing immesurably - and thus your game sessions. Understanding archetypes and common mythic elements will make your writing much more dynamic because you'll know much better how to use archetypes to better effect and how to avoid stereotyping characters in your writing and sessions.