The 100 Day Project is perfect for designers, writers, and any other creative.
https://designobserver.com/five-years-of-100-days/
I'm frankly surprised that the 100 Day Project is not embraced more by public libraries. One library that does a 100 day project is the Daniel Boone Regional Library. Kudos to them.
Suleika Jaouad explains how the 100 Day Project helped her during a particular low point in her life in The Book of Alchemy.