My nephew wants a new case for his iPhone 11 for Christmas because the one he has right now is letting a lot of dust in and he constantly has to remove the phone out of the case to wipe it clean
sadly, I may not actually be the right guru for this one; my favorite cases by far are merely thin little soft TPU ones. they add very little thickness to the phones, and are mostly just to ward off scuffs and scrapes, while being able to slip art, including stickers, between it and the phone's back, without removing the stickers' backing.
but primarily, they serve to give me a different texture/material for said backs, so the phones aren't as slippery for me. I just don't want them to slide around off the desk/book/etc, or out of my hand.
that said there may be something to be said for making your own. apparently, mixing corn starch into liquid silicone (like with the caulks from the plumbing section of a store) to turn it into a sort of putty/clay-like consistency, and shaping it around the phone in question, cutting out areas for the cameras/etc, and letting it harden.
I think I'd like to figure out how to make it putty-ish and workable, and black, and then make a super thin one around one of my droids in particular... and then paint onto it with like. micro-glitter or flakes or something, like as if I were working with resin (or fancy nails-painting) and then add another super-thin layer outside that, to laminate it.