This is the hardest and most invisible kind of editorial work, tightening each line of prose and each paragraph until it squeaks. And when I'm done, chances are almost nobody will be able to tell at a glance what I've done, or how I've done it. But the book will be tighter and leaner and read better.
Meanwhile, I am having tons of fun zorching prepositional phrases, unnecessary stage directions, and instances of the word "said." It's nice to know I'm a better prose stylist than I was four years ago.
Also, it's important to remember that this is fun, that my work is play, and that if it isn't, I run the risk of becoming the kind of dire hack who churns out unaffecting fiction by the bucketload.
Actually, some of the secrit projekt side work--which more or less amounts to role-playing, and I'm sure some of you will find it eventually--is reminding me of that. Because it's fun getting to know a character from the inside, talk with their voice and wave their hands around.