If you've been writing novels for any length of time, you've gotten stuck. I'm not talking about writer's block, I'm talking about STUCK. When this happens to me, it means 1 of 2 things. Here they are, and here's what I do about them.
1. There's a foundational problem with my plot. (Goal, motivation, conflict, stakes, etc)
I try to make sure these are solid before I start writing, but sometimes I'm wrong. This is my least favorite kind of stuck because it sometimes means going back and making major changes in previously written scenes.
a. Diagnose the problem. Go over plot basics and see where the story is falling short.
b. Go to my writing library and pull out books (or chapters) on the subject. Read and weep--Ahem--I mean apply.
c. Brainstorm possible solutions with my critique partner.
d. Once I've decided on the appropriate "fix", either go back and make changes or make a note to do so in re-writes.
2. I have no idea where my story's going next.
a. Go for a walk, drive; throw in a load of laundry and daydream about what could happen next until I have a plan I'm excited about.
b. Watch a movie or read a novel, keeping an eye out for plot developments that may work for my story--the entry of a romantic threat, an illness or injury, financial setbacks, family secret, etc.
c. Brainstorm possible ideas with my critique partner.
d. Make a list of possible scene ideas.
d. Put the scenes in a logical order. (Complications should go from smallest to biggest). Some writers use scene flashcards, some simply list them in order. My personal favorite is (for lack of a better title) scene bubbles as pictured above. I shade the bubbles when the scene is in the hero's POV and switch the scene order as necessary by changing the arrow directions.
What do you do when you get stuck?