I think it's also important to add productive tasks your your free time that you have fun doing, that way you can feel productive even in your downtime. This is especially effective if your normal work doesn't feel very fulfilling.
My current hobbies are beer/soda/kombucha brewing, hydroponics, maple syrup, forestry, and small electronics. I have a huge amount of fun working on that stuff, it keeps me in shape, and I feel productive regardless of how my actual work that I'm supposed to be productive on is going.