Oh, timely post for me because I'm thinking about this more because I'm about to tackle " tidying" my jewelry and am thinking about what I want to keep and wear, and why.
I do mix, because my wedding and am engagement rings are gold, but for other jewelry I've gravitated to mostly silver( with emphasis on muted silver, pewter tones).
I don't wear bracelets/ bangles much if ever, and I feel necklaces are " farther away" so they are less of an issue even I i were in matchy mode, and don't clash much, but I do always wear a watch on left. Even before I switched to silver jewelry, my favorite watch had been mixed gold and silver metal and black. I have acquired some mixed metal costume jewelry I love, too. So I think I have a sugar eye for that. It might be subliminally because of the better blend with my gold rings, or just because I have cool to neutral coloring and don't choose a lot very shiny silver.
So I think of keeping an eye out for just the right mixed metal look as a kind of signature style, and also maybe one way to rein in the amount of jewelry.
That said, I Akso havd dime pieces with gold or more bronze tone because either the pice was a perfect style( for necklaces, length and weight to work with tops) or I like how they look with certain color clothing.