In settings where I use D&D, I'll either use the standard generic 3.5e elves, orcs, etc. or I'll model them on the elves, orcs, etc. of the D&D Cyclopedia/Mystara Gazetteers.
For my old, now-non-D&D Etan campaign, the "humankin" races are cosmopolitan to the point where even the barbarian clans...