You may be releasing too early. Do you tend to hit "fat" shots?
I feel that the trail wrist stays bent through impact,so I tend to focus on that during the approach to impact. I don't think about the lead wrist.
Perhaps the best training aid for the trail wrist position would be Greg Norman's "Secret." When you wear this device it keeps your trail wrist bent.
Currently,here is what I do:
Set up to the ball,pull the trail shoulder back so the shoulders are parallel to the feet and then lean into my forward foot (65% of my weight);swing with a good shoulder turn and hold the trail wrist bent until impact;then,enjoy the straight ball flight