Video shows stockinette double knitting. I knit one needle on my 2-socks-in-1. Note how the left yarn (for the outer sock) always stays above the right yarn (for the inner sock)
by Crochet Cocoon
by MamochkinKanal
by Preeti Creations
by Jalie Sewing Patterns
by Ratchadawan Chambers
by TejiendodeCorazon
by Sheruknittingcom