I didn't really have "promoting rationality" in mind; when I'm shirtmaking and not pressed for time, I aim most for "wearable and accurate self-expression", followed by "maybe eliciting a flash of recognition from a very tiny percentage of people who see the shirt".

For my own purposes, the ideal respondant to this prompt would have to be able to read my mind and see what I overlook, but any luminous aspiring rationalist might also be able to provide insight.