In Craft & Technique, one of Paul Raymond Martin's little writing instruction books that I keep pushing on other writers, he said something that simplified the whole business of plotting beautifully:
"There are three elements to every plot: Get your character up a tree. Put tigers under the tree. Get your character out of the tree."
I like that, although tigers and trees are a bit tame for me. Dump a bunch of injured characters into a sinking lifeboat, surround the boat with starving sharks, and then send in a cat 5 hurricane before they try to get out -- that's more my style. Still, if you're having trouble with roughing out the basic plot of your story, Paul's three phase approach can be a great starting place.
One of the books I just finished had a plot tiger running around in it that I didn't even see until the third pass. Even stranger, the tiger was setting, not a character or active conflict. The thing was, this one aspect of the setting kept bugging me, and not for the usual reasons like I hate writing it and would that everything could take place in a dark featureless void etc. It sat there acting like a big lump until I rearranged a scene and then wham, it snarled in my face. I hate making changes, but I took the tiger off its chain and let it run. The end result was amazing stuff that didn't alter the story but actually pulled it together, almost as if that was the way it should have been written in the first place. Whether it was the subconscious parallel plotting or just pure dumb writer's luck, I was glad it happened.
Does this happen to anyone else out there? What sort of plot trees or tigers do you find in your stories?