The closest I have ever come to having a set priority to separate cards into more of a “PC” is all cards from my favorite team, all cards of hall of famers, inserts of all star players, and rookie cards of all star players. I collect baseball and basketball so that would be for each sport.
A few things there that have stopped me are the HOF standards for baseball. If I stuck to this, I wouldn’t be adding all cards of some of my favorite players growing up. I grew up watching baseball during the steroid era. So Clemens, Bonds, Sosa, McGwire, A-Rod etc don’t make the cut. I could always make exceptions for them, but I think my likely OCD symptoms require me to have a set system. The other issue is some sets have cards in the base set that might as well be inserts. Some of the Finest sets with the Gold cards come to mind.
I probably need to eventually do something though. Going to need new boxes sometime in the future as I am coming near the end of both my basketball and baseball boxes. Might be a good time to actually do something once I run out of room.
And I am heavily debating putting those PC cards into binders for those that fit, and then a separate smaller box for the thicker cards.