Little bitty doujinshi produced for my patrons last year!
For very short comics I always think of feelings, moods, emotional states. Something that can be a complete thought in the visual equivalent of a paragraph. I know I teased the comic would end up being Sailor Moon, so those were my starting parameters: Sailor Moon characters + something exploring feelings.
I settled on a very simple contemplation: how excited must Makoto have been to move to highschool and finally, finally get to wear the same uniform as everyone else. As a character she struggles so much with being seen as “too big” and forever standing out for it, I can see this little detail meaning a lot to her.