I'd say the key to a good looking organic texture is controlled randomness. Nature and organic forms are chaotic by nature but always follow the rules and patterns sometimes. Once you find them, you just have to try to reproduce them in Substance Designer. It's just the best tool for the job, perfect to control primary secondary and tertiary forms, individually. All of that plus the procedural workflow helps you to achieve what you need, whether that is imitating the natural erosion and fracturing of the rocks or controlling where the moss grows. I don't have a favorite noise pattern, I like to tweak the common cloud noise in various ways if possible from the same source node, keeping memory usage low and being able to create different materials just by inputting a new seed.