Well. I just unlocked Sleight of Hand and Double Tap... I mean...
I usually find most standard drills aren't useful in the airsoft sense. Recoil is usually very light (or non existant), and since you only have to hit your target once, using many shots isn't useful (although that's off-balanced by the fact that magazine capacities are often twice if not three times as large as the actual weapons). Mozambique is nice, but a bit overkill (although it does help when people don't call their hits!
) and I just started trying Center Axis Relock again (with handguns, no sense in trying their long gun stuff, but even CAR focuses on dumping rounds down range as quickly as possible)
I try using off-balanced and unconventional shooting stances (examples being: Sitting down (On the ground, where you can't get as comfortable balanced position as prone), leaning around corners, and trying to fire with exposing as little as possible (IE, whenever you don't have room to get a nice stable weaver and the like).
As far as practical airsoft drills, I try something similar to Bryan, only with about ten targets, and specifically trying to get the drill of reloading as quickly as possible without dropping a mag.
Also, I tried using a Failed Mag drill :P Randomly not filling one magazine completely with gas or no gas at all. Then having to rapidly reload the magazine and rack the slide.