So, how would one go about making greebles like this? Would it just be manual extruding of a tube, or is there some more efficient way to go about it? Currently using Blender 3D because it's GOAT.
Your best approach is thinking of it in terms of modularity. You need just a small set of bends, straights and connections to be able to joint together a complex pipe network.
This way everything is already UV's on the level of modularity and you circumvent what this noob >>507286 is talking about.
Like If you're gonna do sprawling city streets, you's make intersections T-junctions and straights and so on.
Also whatever you do not attempt to make a actual replica of what you see there. That's not what greebles is about.
Making something covered in pipe and shit is very easy, making something covered in the exact same pipe and shit as something else is super hard and will make you hate life.
David Lesperance has a tutorial on Gumroad where he models a jet engine with all sorts of cables and pipes and stuff. Might be worth checking out. It's for max, but the concepts shouldn't be too hard to carry over.
see the following pictures
first make a cone and divide it loads, and trace the shapes of the wires you want to make,press p to separate
subdivide and smooth as necessary