But, until we have the option of a perfectly renewable society, consider downcycling an option. At least it's not creating more waste by incorporating new products.
Thus I present - the Thrift Store. Also known as a "secondhand shop" or "resale store" or "consignment boutique", depending on how upscale you want to go. Finding a good thrift shop can be a lifesaver. And it isn't just full of crap that no one wanted, sitting half-broken and covered in splattered paint. And you don't have to be dressing like a Boho or punk to find clothes, either. Some larger thrift shops can have really nice things.
I live near an AmVets, which is larger than most restaurants and has the entire middle dedicated mostly to clothes. That place is dangerous! Goodwill and Salvation Army can be hit or miss, depending on their size and location. And don't discount small local shops. Check them out, as quality can vary, but sometimes you can find a little gem. There's one near my house in which I have scored 2 pairs of like-new NYDJ jeans (normal retail between $70-$90) for about $20. And those were the expensive pairs. I haven't bought jeans at full price in years.
I mainly go for clothing, since that's where a lot of money gets spent on new things. I've had some serious scores on that front. I found a like-new, floor-length evening dress, perfect size, for $15. When I wore it to semi-formal this year, people couldn't believe it when they asked where I'd found it. There was also a Victorian/SteamPunk coat I found ($15) but had to pass on at the time. I'm still kicking myself on that front. Halloween, school play, or other costumes can also be made.
Here's my normal scores - yesterday I hit AmVets because I was in dire need of jeans. I found 3 pairs, like new, one with a small rip which I can easily sew up. I also found two perfect purses and a business-casual skirt. Total? $30.
It's also great for basic home ware if you're moving in to a new place or setting up a dorm or apartment. Cheap china, cheap glasses, silver, and little furnishing things. It's also great to find scarves for furoshiki projects. Don't tell my friend, but one of her birthday gifts came from there! I found a gorgeous china vase, wrapped it in a purple scarf furoshiki, and it looked like a million bucks.
A few bits of quick advice from a veteran thrift-shopper.
1) Bring cash. Most stores don't have credit-card machines and the ATMs are expensive.
2) Wear a skirt if you're a lady shopping for pants. Some stores don't have dressing rooms and this is the best way to make sure things fit,
3)And be sure things fit. You can't return them.
4) Look for tears, stains, or other defects before purchasing. Consider learning some basic sewing skills to be able to pick up deals.
5) Have fun! At least you know no one else will have something exactly like you.
Also, when you have things you no longer want, please consider donating them. Even if they're ripped to shreds, Salvation Army and Goodwill will take clothes and sell them as rags or stuffing for car upholstry. At best, someone else will love your old shirt, purse, or shoes. A lot of these shops make money for charities, so you're even doing good work there.