20. Know Which Breaker to Turn Off
When you finally get around to putting in that dimmer switch, you won't want to be stumped by a poorly labeled breaker box. Ditch the pencil and paper chart—you're not changing your wiring anytime soon. Instead, write directly on the metal next to each switch with a fine indelible marker. Have a friend plug lamps into all the sockets in a room and tell you via cell phone which ones go dark when you flip a switch. Then, be specific ("sofa and window walls only" or "kitchen minus fridge") when you jot it down.