Thanks to RoyBatterian for making me aware of this.

First, make sure you have RoyB's GECK Extender installed, it will simplify things and stop the procedure from pausing every time it detects harmless errors, which it will, a lot.

Second, check out this article from the GECK wiki.

The specified "CTRL+F4" method in that link didn't use to work for me, but now it does *shrug*.  An alternate way that will take much longer (but is a very simple solution) is that after loading the plugin you want to export face textures for, click on "Character" at the top, then "Export NPC Face Textures".  You'll get a bunch of .dds and .tga files dumped to the folder structure that they need to remain in for them to function. The .dds files are useless and should be deleted. Now, the .tgas do need to be converted to .dds using DDS Converter 1.4 with options "DTX1", "Repeat" and "Mipmaps" checked. Once converted, you no longer need the .tga's in the final folder structure.

If you used the global "Export NPC Face Textures" option, delete the Fallout.esm folder that gets generated,  you don't need it (and generating it is what makes that option take much longer).

I have noted that these only work if the last ESM that the NPC actor record is found in is the one that these textures are created for (so for example, you have Easy Pete in the "New Vegas Redesigned 3.esm" folder generated by the above procedure. If the Easy Pete record was in another ESM that loads after the NVR3.esm, it won't find it and he'll be albino again. This is why I say in the instructions to put the NVR3.esm after all the other ESM's, though it really only has to be other ESM's that have NPC Actor records, and you really do need a patch if you have other ESMs with NPC actor records that conflict anyway. Having the NPC actor record in an ESP that overrides the ESM doesn't seem to cause any problems.

That is pretty much all there is to it.