Some of it is setup, alot is driver skill. A locked or very thick center diff would help as would running fluid that is thicker than an offroad setup in the front. I found lowering the ride height with the downtravel screws and adding a bit of preload to the shock springs helped too. My rc8 had too much body roll in stock form for drifting and street running in general.
The biggie would be tires, something that doesn't have a ton of grip. 1/10th drift tires are generally hard and alot of guys go with pvc pipe wrapped around their wheels or tires. Part of it is cost as PVC pipe is fairly cheap, lasts quite awhile and can make alot of "tires". But also, the more grip the tire has, the higher the speeds and more power you need to drift.
I tried a set of Imex rally tires (these
http://www.imexrc.com/servlet/the-16...dsh-RIM/Detail ). I didn't want drift tires, but thats basically what I got with these. They were fun and alot more controllable than the PVC tired cars I've driven. They didn't last too long though. I got less than 15 packs out of a set before there were holes in them. Thankfully I got them at my LHS for alot cheaper than the online price.