The most seasonally-appropriate pairing I can ever remember wearing (in that it sounds like the ingredients for some Thanksgiving recipe), Xtreme Wear Pumpkin Spice over Zoya Cinnamon:
Fossil of the Death Worm without putting it over anything and I didn't like it at all. I slapped Cinnamon on top because I was thinking it might show through and look interesting, but mostly it really didn't show up well at all. So I'll have to try that again some other time.
I've done a couple more manicures that I haven't gotten around to showing lately. I did Cougar Attack over brown, and mattified it, which I really liked. I thought I had taken a picture of that but if so I can't track it down. And back before that, back in October, I did another Candy Corn Cordial over Retro Red, which was really similar to one I'd done shortly before, so I wasn't too worried about getting a picture on that one.