One of my best gca lessons came from Pete Dye. The "typical" fw mowing line weaves in and out, often shaped by a mound on the inside point. He said his preference was a pretty straight line, that rolled up and over gentle hills (probably 15% or so, not over 30% slopes.) Or even one where the low point is the inside of a very gentle curve, and the "outies" were on the top of a gentle ridge.
While mowing lines look great on plan or from airplanes when they curve around, basically, from the tee (the primary viewing point) a straight line rolling over hill and dale as he described is more attractive. And, straighter lines can be called "fairer" as well, since one shot a few yards shorter than another identical shot usually gets similar treatment, rather than one being in the rough and the other in the FW.