I used to hang until I helped someone do tracking with dogs.  I learned some interesting things that figure into my choice of stash spots.

Scent is carried in moist air, which is why very dry air is hard for dogs to track in.  As the air cools, it becomes more humid and sinks.  So in the evening, low spots have the most moisture - and the strongest scents - but they're also the places where the heavier air settles.  This means that scents move toward low spots, rather than away from them.

I stash my food pack in the lowest places I can find and easily reach, and have some sort of visual barrier like a rock wall or a bunch of overhanging bushes.  These places are usually along shorelines.

My dog tells me whether my food pack is scent-proof.  I leave it open just a tad and let him walk by it.  He usually shows quite a bit of interest.  I close it up and he ignores it.  That's good enough for me.

My food pack includes a Bear Vault (large size) and several different sized OP sacks, which are truly Odor Proof.  It all goes into a dry bag-type pack which I wipe down with lake water before stashing.

Never again will the rock at the end of the hanging rope boomerang back at me!