Chris Ryan, Senior PGA Professional at the Belfry, shows you a simple method of checking if you are gripping the club correctly. The drill will tell you if your grip isn't where you want it to be and what hand is at fault and let you know what you need to fix.
Chris opens with the tantalising promise that developing a proper grip will lead to straighter shots with more power. The drill involves hinging the wrists from the address position in an attempt to raise the club to the horizontal. Successfully doing this is indicative of a good grip. If you are unable to achieve the horizontal position then re-trying using with just a single hand will highlight whether the left or right hand is most at fault. He concludes by stating that golfers need not all have exactly the same grips although they should share an ability to achieve the same angles when the wrists are set.