Do vapor barrier socks work? I love them. I have been happy in a pair of rbh designs VaprThrm socks to 0F inside a pair of uninsulated gore-tex trail runners. I wear the rbh directly against the skin because they are comfortable that way. When I have used less comfortable socks (link plastic or mylar bags), I have used the thinnest liner I could find.

As to whether to wear heavier socks over them.. that would depend on how much insulation you need. Keep in mind though that you don't want to be pinching you feet... too much pressure effects blood flow which is a great way to make it hard to keep feet warm.

--Mark