This pattern is for knit slippers, but I can totally see using a wool sweater and cutting and serging slippers from it! Home Slippers - DIY. this is knitting, but I bet I could use this to crochet some
Inspiration for jumper or cardigan if cut down the middle? And I might cut up and lengthen the inner sleeve seam, this creating more of a side seam at the same time so it's not quite so revealing on the sides.