ORIGINAL: Crazy Horse RVN
The easiest way I've found is to skin the animal while it's still warm. You don't have to exert yourself and there is limited need for a knife. The hide peals off easily. If you allow the animal to rigor you've just created labor for yourself.
I concur, if reasonably fresh the knife time & entire procedurereally cuts down. I also find it faster if the animal is hanging vs on the ground, of which I prefer head down!