With WATER completed, I am now turning my attention to research for the next book, AIR, and getting a little research done on story as well.
An easy way to get a handle on story - plot, structure, characterization - is to check out movie commentaries featuring the writers or directors. In particular, pay close attention to what scenes they say they edit or delete, and why. I find this an invaluable reference for the art of tight storytelling. Sometimes they will also mention why a scene needed to be added. This is important especially as an aid to character continuity. You don't want your character to jump from point B to point Q on his arc, or your reader (or viewer) will go, "Huh?" Hence, the addition of a missing scene to illustrate character growth.
Movies and tightly plotted books are not all that different. The tools are a bit different, but you are still telling a story, and cutting away the deadwood helps your story shine. The next time you watch a movie you've seen before, make sure you watch it with the commentaries enabled. You might be surprised how much you learn!