Specifically, between trail runners and lightweight boots (or something in between).
Most of the other stuff I pack is pretty standard (nothing very exciting). For example, I've always been an MSR Pocket Rocket guy when it comes to stoves.
I finally broke down and bought a pillow (Sea to Summit Aeros Premium), which weighs less than 3 oz and packs down to nothing.
Another thing I've never previously carried and am now considering, is some kind of satellite communication device (e.g., Garmin InReach Mini, etc.). My wife would really appreciate this. But, if I go with the Garmin, it will set me back another $400 (plus subscription fees). That being said, I could Bluetooth pair it with pre-downloaded maps on my phone as well as a Garmin watch, which would be pretty cool.