[mcc1ane]

or 5 times the lock (power) button only

[tessela]

… or you can just close your eyes, and move your face around. The device will not unlock if you're not looking at it and after 3 or 4 tries will ask for the password.

[runjake]

Right, there’s a multitude of ways to trigger a passcode requirement, but the point here is quick/immediate procedures that can be learned into muscle memory.