I know the subject has been written about before but I remember reading some views about them a few months ago so I thought I would give the idea a try. I started by using my ordinary day to day cotton socks and after being pleased with the result I popped down to Millets and bought a pair labelled as liner socks, I wanted longer socks, my day to day ones were too short for me.
My personal view now is, why didn't I try them years ago? Until a few months, I only ever wore one pair of socks, wearing two is so comfortable.
I also now wear two when I go off road running, this works well for me, my feet feel good at the end of a run in a way they didn't before.