In this video golf lesson, Phil Blackmar offers advice for high-handicappers who have trouble getting the ball out of problematic deep grass.
According to Blackmar, most beginning golfers make the mistake of taking too short of a swing and then coming at the ball hard, which is the result of too much tension in the arms. He demonstrates how, instead, the arms need to be relaxed to allow for a flowing movement, much like the motion of a pendulum.
It is also important to close the clubface slightly rather than opening it, since that will help it to cut through the grass.