Hit balls by taking small swings with just your left hand (for right-hander) and concentrate on not letting the clubhead pass your hands at impact. At the same time hit down on the ball. This will help you get the correct impact feel. As you get a better feel for this lengthen your swing, as your swing gets longer your hands will naturally turn over. Without seeing your swing it sounds like you are trying to either force your hands over or trying to help the ball get up by hitting up into the ball. If this is the case, teach yourself to hit down and through the ball, it will produce amazing results. Specifically power and accuracy.
Good luck and I hope this is helpful.