Here we are keeping the strategies and hints for HNM hunting.
(this information comes from ZAM)

[IMPORTANT:] Incapacitating different parts of the NMs also require you to stand at different positions appropriate for the part you want to break.

EXAMPLE: To break Buffalos Left Horn, the characters trying to break its Left Horn must stand on the left side of Great Buffalo. The characters trying to break its Right Horn must stand on the right side of Great Buffalo.

Here's the SE official page

[2012-05-05: Why keep old information? I removed the old stuff. This table makes more sense, thanks to the person who added it.]

Updated Information:

		Head		Right		Left	Legs		Special Rt	Special Lt	Special Bk
PGL		Concussive Blow				Demolish					Dragon Kick*
GLA		Spirits Within*	Savage Blade				Flat Blade		
MRD		Skull Sunder	Storms Path				Godsbane			Maim
ARC		Bloodletter				Leaden Arrow			Gloom Arrow	
LNC						Heavy Thrust				Impulse Drive	
*Monk and Paladin only

Mobs breakable body parts (mostly bosses and the like)
		Head		Right		Left	Legs		Spec. Rt.	Spec. Lt.	Spec. Bk.
Chimera													Tail
Princess	Mandibles