A 20 minute walk to start the day always seems to clear my mind and focus me for the rest of the day. I don't always mention it on here because it isn't necessarily a big workout or run, but I do feel it's a benefit to my mind and body. I cover a variety of topics in my head during the time and simply walking out the muscles feels good. I plan upcoming workouts, runs, classes for my students, go over the family schedule, think about how amazing my wife Maura is, etc.
I encourage you to walk a couple times a week even for just 15-20 minutes. My only suggestion beyond that is that you walk a little quicker, not a slow pace. It should look like you have a purpose, or that you are trying to get somewhere. This increased pace will up the heart rate and loosen the muscles, as well as start your mind in various directions.