Gin we have found thermal socks in Poundworld/land and Home Bargains in the past which we've used for gift bags for the homeless shelter. I don't know whether they are high quality or not, but DH has also bought them for hillwalking and he says they're fine. They also have more feminine looking ones for women which are a bit nicer than the standard black/grey.
In fact, we have made up the gift bags in the past almost exclusively from those shops. We always put in socks, gloves, hat, lipbalm, hand sanitiser, toothbrush, toothpaste and tissues as the practical stuff and then sweets, biscuits & chocolate as Christmassy treats. The small tins of danish butter biscuits in those shops apparently always go down well because the tin keeps the biscuits fresh and is then useful for keeping stuff in afterwards