The first board I tried laying out in Eurorack was Yves Usson's 'Minimoog VCF'. I was working with habits from the pedal world for this board -- with pedals, wires are run for the jacks, normally. It was also rather weirdly laid out, and looked like a hot mess.
I later worked up another layout... embarassingly, I forgot to take photographs of the finished module. Too excited, I guess. I did take a photo of the paper templates I printed out, to check that everything would fit okay. I was just starting to use the sandwich PCB technique, and had not yet discovered pinhead.lbr, which is why the pads for those look decidedly odd.
The ladder transistors are pretty plainly laid out in a horizontal row, along with the ladder capacitors, and all the trimpots are along the top of the PCB. I kept the knobs-top, jacks-bottom layout on the panel, but compressed it a bit. (On reflection, this layout might come from wanting a MOTM modular, back when I was a dead broke teenager with no money whatsoever.)