Create a new emoji character. Go through a brainstorming process to come up with useful new emoji types. Design them, in the style of different emoji / OS alphabets (Google, Twitter, OpenMoji…).
Study the emoji submission process:
https://unicode.org/emoji/proposals.html
Get inspired by actual emoji proposals : https://www.unicode.org/emoji/charts/emoji-proposals.html
Get inspired by the OpenMoji styleguide:
https://openmoji.org/styleguide/
Related reading:
Ellen Lupton, Design is Storytelling, p. 100.
Jennifer Daniel (March 23 2020), Talk to Me: The Evolution of Emoji, Google Design