Don't clinch your left when you try it for a few times(100). So you can get the whip feeling down, then start to clinch your fist right before it full extends. Do that after you get the whip feeling down, and do that for a few times. Then it becomes natural and you'll always throw it like that.
Then again, I am ambidextrous so it's different for me but I prefer to use my right hand.
I switch hit btw. Two, almost totally different styles for both stances.