So, I feel like I have a pretty good grip on my strengths and weaknesses as a writer.  I'm pretty good with character development, pacing, and exposition.  One thing I've struggled with, though (and reading the Dresden Files has made me really want to get better) is setting up a good, layered mystery story.  Something just complex enough that it's tricky to figure out, but not so complex that it seems like the author just artificially added more bends in the river to make it seem more complex.  Jim does a stellar job of this, and frankly, I'd kill to know what his secret is.... and no that is NOT a literal statement to be exploited by any fairy queens that might be reading this.  You know who you are.

You guys have any advice you'd be willing to share?