1) Momentum in writing: A good book builds momentum with every scene and every chapter. It's the kind of momentum which keeps the reader turning pages when they should be sleeping, cleaning the house, or doing the taxes. It's what makes the reader miss their train stop on the way to work.
But, momentum can't just build and build at a break-neck pace (well, technically it can, I just don't like it). I've read books like this (many are best-sellers - Dan Brown comes to mind), and I don't mind putting them down because I know it's just going to be one crazy plot point after another and that there's pretty much no chance the climax and the resolutions I'm looking for are just around the corner. So where's the line? To be honest, I'm not exactly sure. I know it when I read it, and I think it has to do with the right mixture of emotional tension, external conflict, and foreshadowing.
What do you think? Do you agree that purely action-driven books which try to eliminate natural pauses where the reader could put the book down can sometimes go too far?
2) Writing momentum: This can be so hard to build and can so easily fall apart. When conditions are right, I can really build some serious writing momentum. But one weekend off can lead to a week can lead to a month.... And once the momentum is gone it can be hard to get back into an old MS, to find the voice which came so easily while I was in the groove. Sometimes there's nothing I can do about breaking the momentum. A family emergency, a really bad case of the flu, or a tight deadline at work could keep me from writing. Other times though, I'll set aside the writing to enjoy a weekend outside, or I might decide to leave the laptop at home while I go on vacation. Whatever the reason for breaking my momentum is, I have to figure out a way to get it back once I'm ready to start writing again. Usually, this means reading the abandoned partial draft, doing some editing, and maybe even a writing exercise (writing out the background story for one of my characters for example).
How do you re-find lost writing momentum? Do you have any tricks to speed up the process?