Christopher J. Hillger
These might not work for everyone but, personally I deal with writer's block by starting with how the story is going to end. This gives me a point to move towards and helps me keep the flow going.
Another trick I do is write a brief summery of each chapter. That way I have the general focus for each chapter in the book. So if I am having trouble with "What comes next?" I just look at what just happens, what is supposed to happen here and what comes in the next chapter.
My last trick is to look at a scene and think "How is this different in my head versus what is written down?" This helps add detail and can get the writing flow started back up if I'm stuck.