A few guys with some rope, stakes and boards. A well planned agenda. A basic knowledge of geometry and surveying. Some flashlights.
A cool hobby for science geeks, it seems to me! Gets your technical and artistic cravings satisfied.
It would be extremely difficult to plot out a complicated design amidst crops and then execute the flattening of the crops accurately without setting up transits, running guide lines, pulling lines with expanding or diminishing arcs as in a French Curve (as some CS designs have) and leaving a huge mess of plants disturbed and ground trodden outside the designe itself. That sort of thing may be evident in some CS's but not in many that I have looked at. (in pics. never saw one firsthand) And all this is accomplished without being noticed, spending hours with flashlights in a field.