I cut up a vintage fair isle sweater to make these scuff style slippers. I recycled a piece of leather for the soles. I glued the sweater to the leather, then sewed the whole thing together, first with a straight stitch then a satin stitch. I did a single crochet edging on the top.
I’ve found a really nice seller on Artfire, resweater, who ships quickly & has good quality sweaters. Living in SoCal it can be tough to find wool sweaters at garage sales & thrift shops.