My quilt guild has a lot of people who donate unwanted fabric. One member cuts them up into the pieces needed for a quilt and each member can pick up a 'kit' to do and bring back to donate. Also, we have a UFO (unfinished objects) that members donate. Other members can pick those up and add to it and finished them for themselves or donate it for our charities that we give to.
For art quilts, I have a friend who works in the custom drapery department of a department store. She gives me the sample books that have been out dated. I separate them into books that are 100% cotton, etc. Most of them are beautiful fabrics. I have had to tell my friend to let me catch up before she gives me more books.
Being frugal is a good thing. And I know I need to practice that more. Thank you for this thread. I hope others will contribute to it also.