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
Knitted Centre-Outwards Spiral pattern by Elizabeth Jarvis. With this sort of ombre wool, this looks very cool.
Ravelry: fallmasche's Mrs Garter - love this!