It was a few years ago that I was asked to construct a sloping white picket fence at the side of a driveway
The owners wanted the pickets to be lower at the center giving a scalloped effect
The first time through, I put the middle picket in place then followed a string line stretched between posts and attached to the center pickets top point….it looked horrible
Each section had a different slope, as the drive was slightly humped, which made it look even worse
When I pulled the nail from the center picket, the string line sagged to its natural sweep
I trimmed the pickets and used this line, different in each section, and the end result left the fence looking like it “belonged” to the landscape.
I simply let Newton set the height for the shortest picket