As you come into the ball, think of hitting toward the target with your right forearm when horizontal to the ground. The mental image is that of thumping your fist down onto a table. Naturally you strike downwards with your thumb up. This will give you the idea of what to do and when to do it. Remember that to apply power in the hitting zone you must delay any work in your swing until your right forearm reaches the horizontal position, thumb up.
Study the photo on impact to see that the shaft is angled well forward. If you finish the shot with your weight on the outside of your left foot as shown in the photo, your swing will come into the ball from the inside.
As this is a lesson on how to use the right hand, the action can be utilized effectively to create intentional Fade and Draw shots. For a draw shot it is a matter of working your right hand finger knuckles toward the ball as in a punch and turning the first knuckle of the left hand into the ball as well.