Definitely the thinking. I enjoy the planning part of the project when I visualize what the animation is going to look like at the end and just let my imagination fly.
I always start creating assets in my mind before even opening a 3D software. I think of still frames and how I am going to animate them. I think of various rendering styles and compositing techniques that may be suitable for this specific task. Proper planning can save hours of work in future. So, basically, I have a final idea of what the project is going to (or at least what I expect it to) look like at the beginning of the project.
Do you ever get nearly to the end and think this isn’t working? Then what?
This actually happens a lot. The frustration after putting tons of work into a project and the pictures don’t match is so real! The picture on my screen and the one I have in mind. And there’s only one way to proceed for me – delete everything and go back to square one, and do it all over again until the pixels on my screen start making me less angry. I love 3D animation for this, there’s always an answer why it’s not working right, you just have to find it.