Turn Cook-Cook into Gordan Ramsey
In NV, there's an NCR quest where you have to collect three heads, one of which belongs to a Fiend named Cook-Cook. In order to save yourself some trouble by taking on the whole gang at once (they are in a burnt out building with some pretty great cover), simply save your game and snipe his prize bramin, Queenie, from a distance. This will send Cook-Cook into a factionless murderous frenzy and he will attack his buddies who will, being the kind ladies and gentlemen they are, will attack him right back. After the commotion has died down (pun intended), you can either snipe the survivors from a distance or move in and mop up.
I don't normally like to use VATS, but I use it just for the targeting of the cattle, so I pop the right one the first time, exiting out of vats once I am pointed right at the one I need to kill.
I recommend the savegame just in case one of the attackers mangles his head. You need it intact for the reward.