Filth Wizardry: Recycling containers with crochet. So fantastic and so easy if you have basic crochet skills. All you need are empty plastic containers (don't need to be clear), a hole punch, some yarn and a hook!
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