1. Please suggest
  2. Walk through a park pretending that you died a hundred years ago and God gave you one free day to silently observe life on Earth
    Suggested by @bjnovak
  3. Call a friend you haven't talked to in a long time
    Suggested by @TT
  4. Two words: DANCE PARTY
    Suggested by @alexandrafiber
  5. Transcendental Meditation
    Suggested by @samantharonson
  6. Learn something new by taking on a project
    Pick one thing you want to learn/improve, then pick a project which requires you to learn/get better at that thing. Make sure it's something you can complete (whatever you define that as beforehand) in the free time you have and then focus on that one thing.
    Suggested by @alden