Almost every bad chipper's miss happens for the same reason: The club bottoms out behind the ball. And a well-intentioned but completely destructive piece of advice is a big cause.
I'm sure you've heard a buddy or a teacher tell you that you didn't keep your head down through a shot. Losing your posture can be a problem, but "staying down" isn't a blanket solution. When chipping, if you keep your head and body still like you would on a putt and restrict yourself from turning through, you're basically guaranteeing that the club will bottom out before it gets to the ball. That's OK for putting, when you're on flat ground and hitting the ball on a slight upswing. But a chip needs to be struck with a descending blow. That requires some dynamic motion and body turn back and through the ball.
To get the feel for this, swing the club from hip to hip so both sides match. Turn back and hinge the club up to belt high, then swing through with a gentle pivot so the club goes as high on the other side. Let your hips turn and your eyes move with the shot as the ball leaves. Save the head-down stuff for those pressure putts.
Hank Haney, a Golf Digest Teaching Professional, runs the Hank Haney International Junior Golf Academy in Hilton Head.