Next time you want hang something from the ceiling, like a pendant lamp, use a plumb bob or plumb line. It’s essentially a pointy weight hung at the end of a string: you mark the floor or table with masking tape where you want the item to hang, let the plumb bob hang from the ceiling until the tip is right over the spot, then mark the ceiling where the string is. Now you know where to put in your anchor – low tech but it works every time!