The Pre-existing storyboards

Mostly for the Case of Steven Universe, When it comes to making a Special that commemorates the Titanic's Sinking. History has done most of the storyboarding for them. In the Form of various illustrated media of the sinking.

The Steven Universe production crew can simply derive some scenes from these illustrations. so would the mood of each scene.

Though I have a felling that a Titanic special would be too depressing for such a show. It would even have themes that would seem dark for a show of such kind.