I like to do what I call mind-candy or life-candy. Simply, it is just to engage in enjoyable acts.
Some of mine are: Watch an engaging documentary, read part of a book, take my laptop to an interesting place to work, (museum, park, cafe with a great view) cook a great meal or even buy a snack I love. Have coffee someplace nice, go for a walk in a scenic area, call an old friend, play with a dog.
I also like to watch documentaries or other factual programming. I DVR nature shows--the life of the ant was a good one--and sometimes even play them in the background while working. Being a skier and outdoor enthusiast, watching some ski movies pumps me up and helps me work. (Warren Miller movies are my favorites.) This may be more encouragement than brain health. Letting the Dick Proenneke documentaries play in the background is inspiring.
These activities can take a lot of time if you let them, but you can also be done with little commitment. I cook dinner anyway, with proper planning, making a special meal adds a negligible amount of time. Having a meeting somewhere? Do it in a public area of the museum or other inspiring setting.