This would be something that ought to be discussed on People Sit on Chairs.
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." - Richard FeynmanNo Trope Is Too Common has been referred to as Common Isn't Chairs a handful of times on this wiki, which already seems to cover the "PDSOC" idea. "Subversions" to non-tropes (someone wetting their hair, for example) can be parodied, played with etc, so there's a good chance it's already covered by an index (Hair Tropes in this case).
You do bring up a good point about shielding in works, though. We already have Heliotropes for the sun but I wonder if there could be a Shielding At All Times trope index (Grasp the Sun, Human Shield, "No Peeking!" Request, etc) about tropes where someone instinctively, well, shields something.
Your goateed philistine is sashaying towards us. | 🧱

It can be about how a subversion of a non-trope is still a non-trope, like if Victoria is wearing sunglasses but Sally isn't and she's using her hand to shield her eyes from the sun (referring to a bright sunny day of course so Sunglasses at Night doesn't come into play here). Do we already have a page like this? It's not "too rare to trope" because it's about "subversions" of PSOC that are also common.