Well as far as during leveling, skinning on slaves ...

If your doing gathering quests, which many people don't but whatever, your already got mouse move + interact with target going on and looting mobs and letting the item go to whoever until the items are all picked up. Double tapping the move + interact with target will make 'all the slaves skin and one of the loot' (that means they all skill up by the way).

If you alternatively round robin(assist + mouse move + interact with target) you can easily loot and skin after group kills in places like violet hold without much of a thought one on each character. Its pretty damn quick once you get used to it.\

Note that on quest skins (if a pristine hide drops off mobs, but skinners can get an additional one if they skin it) if a skinner that has all the hides and the quest is complete is the looter of the skin. The quest item is lost, you need to have the one that still needs skins to skin it.