A tight lie makes many golfers feel just that - tight.  When there's little grass under the ball, they feel the need to help it into the air, and "helping" creates tension.  This is especially true when chipping: the muscles in the hands and arms tighten, making it difficult to hinge the club up in the back swing, as it naturally should.  The result is a very low-to-the-ground swing and, more often than not, a thin shot that runs well past the hole.

To get the ball up from a tight lie, the club head must be swinging down into impact.  A descending hit produces the contact and spin necessary to create height, allowing the ball to clear any rough or fringe and land softly on the green.

Use the  length of the backswing to determine the length of the shot.  Keep the hands relaxed so the the club head accelerates into the back of the ball.  Master this technique, and you can handle even the tightest lies.