How would you define a productive day?

Today: I went to a new therapist. I wrote in my journal which I’ve been finding vital in these stormy days. I sketched (trying to do it daily in order to enhance my drawing skills.) I went job hunting and applied for a new job. I went to the library and read. And of course, all the minutiae of a typical day. Still, I have that lingering sensation that I didn’t do my best – that I could’ve done more. I tackled my entire daily to-do list, but… shucks, I don’t know. So, how do you define a productive day?