A baby gate seems simple until moving day, when you realize every gate in the house is mounted a little differently. Document each one before you touch a screwdriver and every gate goes back up at the right height, the same day.
Pro tip: Label each hardware bag by doorway name, not just "gate parts," so you are not testing four bags on move-in day.
Watch out: Do not reinstall a pressure-mounted gate at the top of a staircase; only hardware-mounted gates are rated for stairs.