What's your logical grouping of material-processing?

On my third play-through and can see that certain groupings of processing makes sense to keep together (distance-wise). Rubber & Plastic, the 3 'tors (Motors, Rotors, Stators), Cable & Wire, Reinforced Plates, Modular Frames (and Rotors again?). Getting ready to build Computers and makes sense to it with Circuit Board since they both require Plastic. Another other groups that you always have as you progress through the game?