If I like a fabric but don't have a project in mind, I buy a half yard. If I REALLY like it, (it is on sale) and could see it playing a major part in a quilt, I buy 3 yards. By buying half yards mostly, I have a lot of variety. The more fabrics in a quilt the better. The other half of my stash is built by left overs from projects and buying a scrap bag at my LQS when I see them.