Start with this throwing drill — 

Releasing the club weakly is such a common fault, it’s worth revisiting how to correct it. Making a full release is a good way to gain distance—and to cure the slice that afflicts so many of you. Here’s a fun drill I’ve used to free up my release. If you’ve ever played baseball or softball, you can identify with it. I throw a ball underhanded with my right hand while my left hand holds a club steady on the ground. I swing my right arm back and turn to the top, then turn through and throw the ball at my target. I want to keep my posture consistent throughout the motion. This exercise gives you the feeling of a full release, without the pressure of trying to hit a shot.