Waiting room, self-seat restaurant, etc.: where do you sit?
Walking from car to store/P.O./wherever: head on a swivel? (For that matter, survey of parking lot before parking?)
Puttering in your own yard: have you cleared your six. . . in the last few seconds? (Let alone been on the lookout for “snakes in the grass”?)
In home: one ear cocked for exterior sounds?
What’s that in your pocket(s)/”holstered” by your easy chair?
Etc.