Like everything on here, this is my opinion; and like most of my opinions when it comes to motorcycles, it's pretty much spot on: a custom bike's success aesthetically depends on lines, not fabrication.
It's what it all comes down to. Is that fender too high off the wheel? Is that hardtail section an inch too long... or too short? Are there brass taps and pinstriped nonsense where there should be delicacy and discretion?
Brett Gear gets it. These bikes sit right. He's in Australia, and we want to see some of his work in the mag soon.