Sometimes I will set aside an hour or so to play a video game. I understand not everyone is a gamer, but to me it's a great way to relieve stress after a day. Facebook has many games on it - often ones you can do in simple sessions sometimes even with friends. Nice way to unwind - doing something that exercises your mind - but doesn't TASK it as much as teaching. Listening to music or soundscapes helps too. Youtube is full of long compilations of "Waves on the Beach" or "Rainforest Thunderstorm" type of videos that are great for meditation or just relaxing.