Tonz of practice.
All you do is have a sunlamp with soft shadows enabled and crank up the contrast.
I would think the amount of time you’ve been working with Blender you’d know to try to do it yourself first and mainly just asking if you’re not able to do it.
For a Guru, you ask a lot of questions. But it just looks like it would be a slightly yellow sun lamp, with soft shadows. I’m not sure, but it looks composited.