There's not a great place for farming multiple skins from multiple mobs in rapid succession. Everywhere that came even close to that has been nerfed. If you're a tank then you can hit a couple of worg packs (I think there are 8 in each) in Twilight Highlands that you can AoE down pretty easily for multiple skins in a row, but there's only the two packs and they don't respawn all that fast.Have you been to Tol Barad Peninsula lately? The spiders are now skinnable, and there are even more of them being left around than the crocs.
Your best bet for consistent skins in a fairly small area is Tol Barad right after a battle.