What is your approach to system fine tuning with cables and cords ?

Um, room tuning first, talk to GIK Acoustics and Michael Green.

Next, move any wall wart / AC adapters out of your power conditioner's clean outputs.

Evaluate your image. Are instruments able to smoothly go from left to right, or is there a L, R and maybe a center? Is there a sense of height?

PS:

I use the rack mount version of this inexpensive strip for the wall warts:


https://amzn.to/2UcvMuv

or


https://amzn.to/2EDIyga

They filter noise down to 3 kHz, and have great surge suppression. If you use them for the little noisy adapters they add one more filter between your main power conditioner and your analog gear and DAC.