Not as much as you might think, this is not our first project. Almost all of the skills involved were used when he made an inlaid dice tower. The guidance I offered were really more of a refresher and details about the quirks of my tools like the belt sander etc.
He’s just really good at it. He takes his time and pays attention to the details. He has the same philosophy on making stuff that I do — if something minor isn’t right people may not notice, but l’ll know.