Two of the most common errors which cause poor chipping are an improper setup and an over active right hand or left hand for lefties.
Using your lead arm only, (left arm for right hand golfers & right arm for lefties). Hit some chips, very short ones to begin with. Make sure to choke down slightly on the club and put more weight on your front foot than your back foot. (about 70% front & 30% back)
This forward club/shaft lean will help you to swing in a descending motion, allowing the clubhead to pop the ball up in the air. Once you can hit most of your short chip shots solidly with your lead arm, add your other hand, but keep the pressure light. This is a great drill that allows the lead arm to be the controlling arm in the stroke and the light grip pressure in the opposite hand will discourage its over use.
Always remember to “Practice with a Purpose” – Chip Inks, PGA