We started with storyboarding and cutting the song to a 1-min length. Knowing the song's progression helped with assigning timing to the scenes & shots (e.g. skateboarding scene should start with the chorus).
After dividing the work (room scene for Andrey, book world for me), we proceeded with creating the assets on AI. We did not want to do a disservice to the original illustrator, so we spent quite a lot of time on it.
Once the assets were ready, we proceeded to animating. Couple of key things that we did for the animation:
The walk cycle was initially done in puppetry pin, but we pivoted to using different values on transform properties.
We did several close ups of the same scene to maintain pace of the video.
We made sure that every movement had realistic physics: the book bounced when dropped, eases in motions of limbs, the tearing of the book was edited in graph, etc.
To make the animation more cinematic, we added wiggle() to the camera