The perfect setup doesn't exist.
(There, we said it).
There is no perfect setup.
There is no ‘correct’ setup.
There is just the best overall compromise for your preferences.
It’s a common misconception that one day, there will be one final adjustment click and we’ll experience some euphoric setup, where the bike does everything absolutely perfectly, and we’ll all live happily ever after. That’d be nice, but it generally isn’t quite the case.
Every set-up is a compromise of sorts, finding the best possible balance between support, responsiveness, suppleness/compliance, liveliness, stability and traction to achieve the best overall result on any given trail.
For example, a bike set up for outright speed and stability (relatively heavily damped, sprung according to gradient), say for a world cup downhill run, could come at the expense of ‘poppiness’ on jumps or flatter/smoother terrain. Likewise, the setup you like most for sending huge jumps in the bike park (stiffer spring rates, less damped) might feel like it lacks traction or predictability in high speed chunder.
Unfortunately you can’t really have it all - some compromise is inevitable. Stiffer spring rates (and the concordant shorter travel) are more responsive to rider input because they’re better at transmitting inputs from the rider to the wheels, but that also means that they transmit more force from rough ground through to the rider. A 120mm bike will never be able to eat up terrain like a softly sprung 200mm DH bike for that reason, and the DH bike will never feel as responsive or snappy on flatter or smoother terrain as the 120mm bike.
What should we actually aim for?
Realistically, the most ideal setup is when your suspension is mostly doing what you want it to do, and most importantly, not doing anything that you really hate. It’s much easier to fix specific problems than it is to improve something that’s already pretty good. Clearly defined problems have clearly defined solutions - vague problems usually don’t have solutions at all.
Dialling in your setup:
Only make ONE adjustment at a time.