Like after long physical exercises you need to relax your body, same goes with brain and mind. When you work and using your brain for many hours per day, you have to recharge it and calm down. There are many ways to do so:

• Qi Gong
• Tai Chi
• Meditation (many people thinking it is something complicated and you have to sit in a lotus stance, you can do it even by sitting in the office chair)
• Slow physical exercises, stretching
• Nap (Short sleep)
• Walking in a woods, park, listening for wind, birds
• Walking in a beach, listening for the ocean, slow waves
• Listening for relaxation music
• Burn incense (aroma) sticks
• Playing simple games which doesn't requires much thinking
• Owning a pet(s), aquarium
• Let it go (Let go everything, be here and now, don't worry about what is not happened, what can happen, what you still have to do, just ignore, be only in present, only here and only now)

To sum up:

Do slow things, do not think, watch slow things, be in less urban environment, be more relaxed and slower even when you already are, be only here and now, and don't worry.