I came up with these as a way for my husband to not have to dirty up my floors when he came home for lunch and had no time to remove his boots(a lot of lacing up to do). I used a generic brand of acrylic yarn and a J/6mm hook and half double crochet stitches to make the soles. For the sides it was double crochet stitches done in a pattern of 3 dc space 3 dc all around. I incorporated the elastic by carrying it behind my dc stitches like tapestry working. These fit a man's size 10.