Check the guide subdivisions and display settings as well as the sim settings for hair-to-hair collisions. That's similar to other stuff like metaballs etc. when you have different settings for editor and renderer.
I'd probably do it as geometry using cloners and stuff. Masonry follows specific rules which are hard to capture just with textures, at least when you get closer. Of course I have no idea on your design concept...
The corn crop scene most definitely uses cloners with a cubic falloff or something similar. The stalks actually scale/ shrink before they go out of the square area. Otherwise there could be a million things used, with semifiction's suggestion being a good start. Real booleans could also be used, though not in the way most of you probably think they are used... ;-)
The whole look is basically what "thin film shaders" do when driven by noises and changing the light incidence and other parameters that affect the incidence. In C4D you could experiment with the Spectral shader and all sorts of distortion and displacement stuff. Some harsh contrasts could easily produce those smear film structures. You just need to figure out the mappings in C4Ds dated UV handling to pin the input textures.
Mostly: None. Aside from occasional random findings it would be way too stressful trying to follow people and their blogs, Instagram, Facebook or whatever. I don't spend too much energy on it one way or the other.