Hunter pair dodging
Melee attacking a Hunter to death is relatively easy as they're so slow. Here's something a bit more challenging. When you meet up with a pair of hunters, try continually dodging around, trying to make them inadvertently whack each other. It's a pretty enjoyable business and great practice for dexterity of movement. I could've sworn that one Hunter would eventually kill the other; but after testing things again, I think I must have misremembered. Every time I try it now, it seems that although Hunter blood spills all over the place, neither Hunter is actually damaged, no matter how long you let it go on. A pity.
Tunnel entrance
One of the best opportunities for pair dodging is with the pair that guard the tunnel leading to the big dark cavern in level 5. There's plenty of space to move about in, and generally no other enemies around.
Dancing in a pattern
With a bit of practice you can also make a pair of Hunters 'dance' in a repeating pattern of no-contact swiping. This started happening whilst I was pair-dodging. We started falling into a rhythm and I just tried to continue it. The whole three-body dynamic was as if on a repeating loop.
Making them kill friendlies
Finally, correspondent One One Seven has suggested Hunter dodging to cause other nearby enemies to be killed by Hunter swipes, with bonus points if the enemy gets knocked off a ledge, e.g. in the aforementioned cavern. Lead them towards enemies (presumably Grunts or Jackals). Also perhaps you can get a Hunter to knock one of those Shades off the edge in the cavern?