Phil,
I still think about 90% of holes designed today are mostly discovered in that they fit the topo well without grading, other than to build greens, tees and bunkers. Not many golf features can be laid right on the ground without some construction. And, bunkers aren't natural on most sites and tees really aren't.
On my current project, I am probably grading only 4 fw's out of 18 to achieve vision and get my cuts to build greens and tees. A few more flat areas may get touched to improve drainage and a few hilly ones touched to avoid long drainage swales.
I still consider that I found the best holes on that project, and only will use construction on limited areas to build them. The site isn't as good as some in the Scottish dunes or even Sand Hills, which do limit the amount of construction extraordinarily, but the principles of finding good natural holes is about the same through the green on nearly all sites.