WESTERVILLE, Ohio (AP) – Study your surroundings. Find exits. Identify makeshift weapons. Americans are gleaning those tips and others as they pack classes on how to react to and survive a shooting.

If wrinkles are your packing nemesis, Jones has a few tricks. First, she chooses fabrics that don’t wrinkle easily. For dressier pieces like a crisp white button-down, she folds along natural seams ...