This is a bit of a dead-horse with me, but I strongly suggest getting a
Tac-Man target, with a vital insert. Hand a loose T-Shirt over it, and start shooting it, while moving around.
Place it at different angles, try to hit it while moving, etc.
The human "vital" area is actually very small. With a handgun, its, essentially, the ocular window, and the heart - which is smaller, and farther back than most people think.
The balance between speed and accuracy is a judgement call, and teaching people how to shift that balance is key - but, IMO, its really only a valid concern once you are dealing w. a "low B" (USPSA) shooter, or above.