I rarely buy unless I have a project in mind. But when I do buy just because I really really like the fabric I normally buy a couple of yards depending on how much I like it and the price. Sometimes I can imagine what I might use it for and that will help me decide. I don't over buy fabric mainly because I can't afford too and I don't have the room. I don't every buy by the bolt and alot of quilters would say what I call my stash isn't really a stash but at least I mostly know what I have on hand.