You can solve the problem in two easy steps: When your front foot is below your back foot take a normal stance with a “centered” ball position then move your lead foot down the hill and tilt your shoulders with the slope (see the photo below). Setting up this way delofts the club so use a higher-lofted wedge.
In the photo below I’m standing on the beautiful and meandering Shinnecock Hills G.C. site of last month’s U.S. Open. If you’ve never played Shinnecock before believe me when I tell you that for most weekend golfers shooting better than 96 on this course is an achievement!
Drop one ball into the rough another into a normal fairway lie and tee up the third so it’s about a half-inch above the grass (photo above). The goal is to land all three shots in the same place on the green about a third of the way from the edge to the flagstick. (Repeat any shot that misses the landing spot.)