Yep ...Jono's stills tell the story . You want your backswing to have the shaft pointing inside the ball to target line. One, because it makes the club feel light and two because the shaft will parallel the ball target line when the shoulders are coiled 90*. If you maintain clubhead lag (retain the wrist set) and start the transition in sequence (lower body leading) then the swing will flatten bringing the butt of the shaft to point at the ball target line and then the ball (which means it is on plane) before it unloads into impact. Provided of course the timing is right.
So my man, the answer is turn and lift with the thumbs pointing upwards and the forearms rotating just enough to achieve a 45* angle of the shaft during the lifting phase. You will notice immediately how light the club feels because the pull of gravity now runs through the shaft and not the clubhead as is presently the case.