the way of the ninja
For me, zanshin is all the time — even when I'm sleeping.
It also allows me to enter a party, have a drink and sit down, all totally unnoticed — as if I am invisible. Then, just at the right moment, a friend notices me and says, "Hey! How long have you been here? I didn't even see you walk in!"
That's my art. That's how I practice zanshin.