Don’t fight gravity when you clean. You’ll lose. Working from high to low almost always works better in cleaning situations.
When you’re cleaning the entire house, start on the top floor and work your way down to avoid tracking through rooms you have already cleaned.
When you’re cleaning a room, first remove the cobwebs from the ceiling and upper molding. Then dust the ceiling fan and light fixtures, followed by window frames and wall hangings. Moving downward, conquer the furniture, baseboards, and floors. This ensures that any dust shaken loose from on high does not settle on something you’ve already cleaned below. You don’t want to dust the room twice, do you?
Similarly, when you clean windows and mirrors, start up high and work your way down, because your cleaner obeys gravity. This saves you elbow grease and time.
The rare exception to this rule is wall washing. If you start at the top when you’re washing a wall in your home, dirty water will drip onto the lower areas you haven’t cleaned yet, making streaks that will be tough to remove.