I'm in the middle of sketching out a new story, settled on a post-apocalyptic version of our present. The main feature of this environment would be blind, mindless, aggressive and contagious versions of humankind. A variation over the zombie genre, if you want; they're not zombies, but they may as well be for the sake of this discussion.
My "zombies" are mostly blind, but are keen to react to sounds - at least sounds that seem out-of-place in the natural environment in which they live (because I can't have a zombie horde going mad near a river, for obvious reasons). When no "target" is detected, the zombies just stay on their feet, doing absolutely nothing.
Knowing this, the human survivors may have developed ways to attract as little attention as possible. My main colony would be settled in a place zombie-free, but it may be needed to send scouting party out of the safe zone to salvage scraps. In this setting, the scouting party may need passing through an heavily zombie-populated area - or, in general, make as little noise as possible when traversing an unknown environment.
So, my question is: how do you move silently? I'm considering a variety of factors, from using finger-spell or others non-verbal signs of communication to the actual movement itself.
I figured out that the scouting parties would need to walk with the minimum amount of noise possible. I'm considering making them go out bare-footed or just with socks, or other kind of soft footwear, because it should make less noise than the standard boot, but I'd like some reality checks on this. It seems from a shallow google search that even soft tennis shoes may serve well - without having the risk of harming one's foot while walking or running.
Other measures would require tight clothes over flappy ones, avoiding metal objects that can clank together, and so on.
What do you think? I'm mainly concerned about footwear at the moment, but other ideas are welcomed.