"Stump" shooting is basically roving in the woods and taking random shots at random distances--targets can be pine cones, clumps of grass, a leaf, a flower--anything you can focus on as a target (and doesn't have a back-stop that will destroy your arrow). I wouldn't do it with field points though, as they can snake up under grass and leaves too easily (lost arrow). Good points for this are the Judo, Ace Hex blunt, rubber blunts, etc.

This way you aren't fixated on a particular distance--you learn to judge it subconciously.

Chad