In this creation, students would make a copy of this sheet (if sharing in Google Classroom make sure to post in the body of the message - do not paste as a link).
When the students make a copy they have the option at the bottom of the sheet to use 2, 3, 4, or 5 emojis. If the set of random emojis is not "ideal" - students have the option to reset the emojis by selecting Ctrl R.
When discussing this with my wife we thought that you could create the prompts, select row 2 and delete it (removes the directions for Ctrl R) and then print the prompt. You could then select Ctrl R and create a new prompt and print it out. This could create tons of writing prompts to have at the ready.
If you (or your students) are really interested in how this was created, make sure to check out what Eric calls the "nerdy stuff" in the post.
Embedded below is a 1 minute and 53 second YouTube tutorial.