These Hue liner socks are fantastic!  I own 7 pairs of these and wear them all the time with flats.  They stay on my feet really well, even in shoes that are a bit loose.  I think it's because of the little silicone pad just above the heel.  Comparing to nylon socks or bare feet, I've found them to greatly reduce sweating, odor and chafing.  They show a little bit in my low-cut ballet flats, but that doesn't bother me at all.