Wool. Wool has to be everyone's favorite knitting and crochet fiber. And for good reason, it has bounce and resilience, it is water resistant, and it keeps us warm. But raising farm animals uses a lot of energy. How can you use wool in an environmentally friendly way?
Find a local producer--if you're buying yarn from a local farm where its spun and dyed there, or you have a boutique mill in your area that processes wool from throughout your region, use it. You'll be saving on lots of energy it takes to move yarn from wool gatherer to manufacturer, to distributor, to retailer. You'll also be supporting your local economy.
I'll use up my stash before buying any new yarn. Speaking of which, I'm still working on the big blue blanket that I started back in July. I haven't made anywhere near as much progress as I would like to have made by now -- I'm only five rows in, but things have just been so hectic (as usual, I'm trying to do too much). Truth be told, I'm using it to procrastinate at this point, which is just awful. I ought to be working on the baby blanket for my sister, but I'm a little intimidated by the pineapple pattern. I really want to do it because it's so beautiful, but I fear I may have bitten off more than I can chew. I have a Plan B in case it proves to be too much, but ... I really want to succeed, I'm afraid that I won't, and so I'm avoiding it so I won't have to face up to it. I try to keep telling myself that it's just yarn. :)
Also, I just strongly prefer to finish one project before starting another. I can't stand leaving one thing unfinished while turning to another one, and like my co-worker, Bridgette, the project has to sort of call to me. I have to be in the mood to work with a given yarn, etc. That project ought to be calling to me, but it just isn't. I must get motivated.