I rarely experience writer's block if I'm in the middle of a project. It's starting a piece that can leave me stumped.
Mid-writing, I edit the previous day's writing so that I will catch the same flow when I write a new chapter. I also keep an open document on my computer that I call "What's Next." Every time a future scene or chapter or plot element comes to mind, I fit it into the upcoming timeline. When I sit down to write a new chapter, I first consult the "What's Next" document.
If there's a timeline gap between what I wrote the previous day and the next thing I have planned, then I pray through the gap. Praying for inspiration often lands me with a few surprises...things that are better and more interesting than I would have come up with on my own.