Fix the grip, fix the slice

The root cause for the majority of slicers that I see is a weak positioned grip. It leads to in-swing issues that are simply the body’s way of trying to correct the open face caused by the poor grip. The best way to correct it is to see your local pro and have him show you the proper Vardon grip. It won’t feel comfortable for awhile, but it will start working immediately.
For those who slice and have sound grips, it’s most likely a too far inside path, leading to an over the top downswing. This imparts slice spin on the ball and a too steep downswing. Your local pro can help with this as well.