Make part of the time off, electronics free. It is crazy to see how much time we devote to them, so learning to not check your phone every 2 minutes and avoiding the internet as much as possible is a freeing experience. At least for me it was, so much that I do it every year now where I spend a certain amount of time totally electronics free (1-2 weeks usually).

Travel seems like the other obvious to me personally.

The last is to talk to everyone and observe people doing their job around you. I love hearing about what issues people are facing, what things in their life are challenging them etc. I don't mean personal issues, I am more about finding problems to solve. To me that is fun, and it is cool to interact with people that I wouldn't necessarily meet in my everyday grind. You could easily come back with ideas of problems to solve that would be of interest to you. Of course, I personally find this fun, you may not.