Here’s one more from the “I can’t define it, but I know it when I see it” department: staging.
Specifically, how do you 
know when a home has been optimally staged?
Unfortunately, there’s no objective test that I’m aware of (like putting a toothpick into a cake to see whether it comes out clean).
Rather, it’s a question of (subjective) feel: is the home welcoming and aesthetically pleasing?
Is each room shown off to maximum effect?
Is there a flow to the home that pulls you through it, and creates a sense of unity?
Put it this way: if creating all those things is elusive (and it is), it’s certainly easy to identify when they’re missing.
P.S.: And no, staging isn’t about new furniture, fresh paint, or other expensive outlays; the best stagers work with what’s already in the home (for the most part).
