I love what Matt had to say about getting your characters in character and keeping them in character! There's little more frustrating to a reader than having to stop halfway through a book and say "that doesn't sound like Edward/Harry/Priscilla Queen of the Desert at ALL." Well said, Delman.
Kid and I are on our way to meet the rest of the fam damily for a reunion in Disneyland. Now, whatever your personal feelings towards the Mouse in his great house may be, you have to admit that Disney creates pretty airtight worlds. Movies, parks, you name it: the "magic" often comes from complete immersion in such fantastical settings.
And details? Disney is the absolute master of details. Every ride, every frigging fruit stand in the parks is loaded with inside jokes for the astute, hidden gags and Mickeys, anything to keep you from being "jolted" as it were, from the world. Ever been on a Disney ride that has broken down? It's AWESOME. You wonder why they put so much work into an exit sign or a patch of wall that no one sees...but that's what we world-creators need to do. Create something strong enough to hold a plot, characters and your reader's imagination for hours afterwards. This doesn't necessarily mean listing your world's bus schedules of course...but if your character does take public transportation, this means you should know it for sure. Spare no street sign!
So, writer friends, what do your settings look like? Are they movie props to be filmed from the front and put away the second the plot passes them by? Or are they three dimensional, tangible worlds to walk around and play Quidditch in long after your reader turns off the Kindle?
(that's right. I said Kindle. I went there.)