I shop at yard sales. I also buy fat quarters when i can get them cheap. I use my 40% coupons for single cuts of fabric and batting. The craft/fabric stores who issue coupons often will take a competitors coupon. ASK.
If I see a fabric I love, i buy two or three yards. We have Mennonite quilt shops which are high quality/lower priced stores.
I have to paint my sewing room. When I do that I will put my fabric on shelves instead of in bins so I know what I already have. I also do not use credit.