I like the paper plate criteria but also like what Vance said. First shot is always the most important and, if you want to take it a step further, it should probably be a cold barrel shot.

There was an article in a hunting magazine a few years back that talked about preparing for deer season where the author recommended practicing twice a week shooting at 8 inch bullseye targets at ranges from 50 to 100 yards from various positions. That circle seems to be the standard and the program could easily be adapted to handgun hunting.