When I was exploring modular synthesis I basically watched a tonne of youtube tutorials to learn the ins and outs of the different modules I was looking into buying. Same with the ones that I wanted but never could afford, i.e the Mutable Instruments modules. Since everything is modular and relative to what you want to accomplish, I think the first thing one would think of is something along the lines of; do I want it to be musical, or do I want a fun and explorative noise machine? For inspiration I recommend binging on modular videos on youtube, a good place to start is Mylarmelodies.
Imo the best way, at least to achieve something that’s not your “run of the mill synth”, like you are explaining, is thinking backwards. What modules interested you the most? What happens if you connect this cable in a place where it isn’t meant to? Etc.etc. I’ve spent an awful lot of time just exploring, watching videos and trying back and forth.