TO maximise distance you need to be able to create clubhead speed.
A great way to get the feeling of moving the club quickly is to try swinging one-handed.
Turn the club upside down so that you are holding the shaft just above the head.
Then I would like you to swing the club back in to a full backswing position, before swinging down towards where the golf ball would be.
You are listening for a swishing noise.
You want to time your swing so that the ‘swoosh’ occurs right down at the bottom of the swing.
Once you feel that you can control the location of the ‘swoosh’ you can start to turn up the speed of the swing.
By loosening your grip pressure you will be able to increase the speed of the swing.
Ideally you want a grip pressure of about 5/10, 10/10 being a white knuckle ride on a rollercoaster.