With whole roasts, they don't do much differently than what I see most americans do, unless you're cooking a named dish: Rouladen, Sauerbraten and so forth. But it comes in the sides and such that make it German.
One thing, save the rendered fat and offer it with the starch of the meal. On a number of occasions in Germany, my hosts would offer extra fat from the meat to season a baked or mashed potato, even spaetzle once. A little bit does add some flavor, but for my taste, just a little was plenty.