Recently I have been thinking about different lies and their D-Plane and seeing what we can figure out from them.
BALL ABOVE FEET
What do we know about shots where the ball is above our feet?
The ball usually goes left and it's usually a hook.
My feeling is that the face will turn left on the golfer at impact (usually). I also believe that the path almost naturally goes out to the right. I'd also guess that the attack angle is usually a tad steeper which helps that path go out to the right even more.
While living in North Georgia, an area with very hilly terrain, I started to understand how to hit shots better off of different lies.
I think there are two things that need to happen to straighten out those ball above your feet lies. For one, the clubface either has to stop closing on the golfer OR the golfer has to play for the closing clubface. The other is the golfer has to figure out a way to prevent the path from going so far out to the right.
Either that or the golfer has to learn how to play for the draw.
IF you want to hit it STRAIGHT, my suggestion would be to do something I started to do. I would aim the clubface well right of the target at ADDRESS. Then I would open my STANCE at address and swing along the lines of my body. In other words, if I wanted to hit this lie straight I would almost play for a slice. But what would happen is that the face would return close to square to the target at impact and the path would be more square since I was swinging the club left in order to counter its naturally tendency to go out to the right from this type of lie.
Now, if you just want to play the draw/hook from this lie, I would suggest aiming the clubface well out to the right and aim your BODY more like you normally would to the target. This would create an impact where the face would either be square or slightly open and a path out to the right. Most golfers aim everything out to the right and I think that creates a square/slightly open face and a path well, well out to the right...creating a hook that is too tough to control.
BALL BELOW YOUR FEET
The ball here will do the opposite of the above lie...it will go to the right, usually with fade/slice spin and usually goes low. I'd be curious to see what the attack angle on this lie would be since I've never hit either the above the feet or below the feet lies that high of a trajectory. With the ball below the feet lie, my big problem being 6'4" tall is that it's hard for me to not catch the irons off the bottom grooves.
So I think it's safe to say the face naturally opens up at impact and the path naturally goes out to the left.
Thus, if you want to hit it STRAIGHT, I would suggest a clubface pointing to the left at address and aiming out to the right with the body so the path can go out there.
Personally, I play this shot for a fade/slice because I'm more concerned with getting good contact as if I try to get that path more out to the right, I usually don't make very good contact.
From this lie, the ball usually goes high and push hooks on the golfer.
The general rule of thumb here is to move the ball position. They say 'move the ball more towards the higher foot.' On the uphill lie, the lead foot is the 'higher foot', so you want to move it more towards the higher foot.
I find this works quite well. A couple of weeks ago I had an uphill lie with a 3-hybrid and thought about stopping myself before I hit the ball because I had the ball position in my normal, flat lie position. I decided to hit it anyway, hit it well, but it hooked left on me. Why? Because playing it from my normal ball position from an uphill lie made the attack angle steeper, which moves the path slightly out to the right.
Now, one could keep their normal position and 'swing left', but the ball will likely go lower than normal because of the steeper attack angle. This may be a good way to play this shot from a steeper uphill lie if you don't want the ball to go too high and lose distance.
But for normal uphill lies, the golfer may want to have a clubface pointing slightly left and aim their body left in order to move the path out to the left.
I like this picture because it shows the golfer aligning their shoulders parallel to the ground. For me, I don't worry too much about this on uphill lies because my shoulders are pretty much in that position to begin with.
The downhill lie usually goes really low and often a flare out to the right.
The attack angle here is steep. I believe that because the ball goes so low. The other day I hit a shot from an extremely steep downhill lie with a 3-iron and caught it flush, yet the ball probably went about 5 feet off the ground.
I think the flare out to the right means the clubface is open and the steeper attack angle shifts the path out to the right, so the push happens.
I do agree with moving your shoulders parallel with the ground. That will help with your contact and low point. Also, move the ball towards the 'higher foot' which would be the rear foot in this case.
Of course, the best way to learn to play these shots is lots of practice. If you can, create these shots on your driving range and you'll learn a lot from it.