Rob:
Everyone does it differently, so you shouldn't take my response here for an indication of how others work, but since I think the question is prompted from an interview answer I gave, I should give some more detail.
For me, it depends a bit on the job. At High Pointe I did the rough shaping for all of the new greens [as I had done for the old ones 35 years ago], but then I directed Brian Slawnik and Blake Conant [on a couple of greens at the end] to get the last 2-3 inches right, and sometimes a bit more than that. There weren't any greens where they started from scratch, partly because they all thought I should do the greens myself like I did the first time around, and partly because we were spread thin last summer and I didn't have either Brian Schneider or Eric Iverson on site at any point, and Brian Slawnik had to be finishing holes for planting while I was out in front shaping the new ones.
And if people wind up thinking that High Pointe is not quite as good as some of my other recent courses, it's probably because I shaped too much of it! I'm working with some of the best greens builders who ever lived, and the whole point of them being there is to take advantage of their talent to make the course better. And I always thought that the greens I sketched out turned out a little wilder than the greens where we just started shaping with a general idea, so it's been years since I tried to draw out more than 1 or 2 greens on a course. I'm happier to just walk those guys through my idea and let them take a shot at it, or, if I don't have a clear idea, sometimes I'll just turn them loose and see what they come up with. [Also, I learned long ago to keep my instructions to them pretty simple -- two or three key points, max -- or I might say two things that conflicted and they would get stuck.]
On most projects, there will be some greens where I ask them not to do much work until I'm there to watch, and others where I tell them to go ahead and rough something in -- sometimes with more instruction, and sometimes with less.
At Riverfront, 30 years ago, for the 5th green my instruction to Eric Iverson was to make it relatively skinny on the diagonal, and try to make it look as different as possible from the left side of the fairway as from the right. I didn't have to edit his first attempt at all.
At Ballyneal, the 8th green is all Brian Schneider's, with some editing from me to soften it for certain shots, but he built the 7th [in about an hour and a half] with me standing right there telling him exactly what to do.
So, in the end, those guys should get some credit for all the cool stuff I get credit for; but the final edit is mine, and I might have saved them from building a few things over the years that wouldn't have been as well received.
That's for greens and surrounds, which I consider the most important part of our work. For bunkers, I will usually stick a couple of flags in the ground or point out to them where I want the bunker, and I will come back to edit if something catches my eye wrong, but most of the creative work on the shapes of the bunkers is theirs. They definitely also add bunkers sometimes on their own, and I sometimes take them out if I don't like them.
For fairways, the whole idea of minimalism is that if I do a good routing, there isn't too much shaping that has to be done in the fairway, but if there is, I will generally direct it.
I did this the same way when I was building one or two courses a year as I do now. The point is that when you've got really talented people working for you, the way to make your course better [and to keep them around long term] is to give them a chance to contribute to the finished product, instead of just softening a slope where you tell them.
We're a team, and the best part of that is that all of them respect each other's opinions, so they will put their two cents' worth in on what the other guy is doing, too.
As to how everyone else works, I can't say for sure, but I can say that most of the Golden Age architects we revere were not on site nearly long enough to see every green contour and bunker get built -- they did the framework of the plan, but they left a lot of the detailing to the guys who were on site. And I firmly believe the best decisions are made by the guy standing right there. But normally I go back often enough to at least give them the thumbs-up myself.