Sustainability in Crochet / Eco-Friendly and Environmentally Conscious Crochet Projects

Dear users, dear authors,
How can we make crocheting more sustainable and eco-friendly? Is that even possible or practical?

Anything is possible. :-)
No, of course there are plenty of ways. For example, you can crochet shopping bags and pouches from yarn scraps—this way, you don’t throw away the scraps, and the bags can be reused countless times. The same goes for old sweaters and other items that can undergo unraveling; the yarn from those can also be reused.
If there’s no yarn left that can be crocheted or knitted with, you can still use everything as stuffing for pillows and amigurumi.