One thing I can say about having our house on the market is that it has never looked cleaner. Every time we prepare to leave the house, I run around wiping down sinks, making beds, picking up toys, straightening pillows, putting away dishes, hiding dog bowls, recycling newspapers, and doing any number of other necessary tasks.
One thing I can say about being a great housekeeper is that it sucks. I'm not cut out for immaculance. (To the best of my knowledge, I just made up that word. Let's start using it and get it added to the lexicon.)