I learned a valuable lesson just recently. I had a backing that I had ordered on line, bought 6 yards of it for applique background blocks and loved it. Recently I started doing applique quilts with a friend as a joint effort. She loved the fabric so much so I gave some to her for her quilt. I then decided that since it was such a beautiful background, I would make heirloom applique quilts to be handed down to each of our 5 living children when I complete my "bucket list" and low and behold, I was down to my last little bit of the fabric. I searched everywhere on line and in LQS's for it and could not find it. Fortunately, someone on this very forum pointed me in the right direction and I was reunited with it once again. I ordered a lot more of it. Now all the kids will each have a different quilt but with the same background. The only time I buy large yardages is when I am going to use it for background for applique blocks or for backings. All the rest, I buy either 1 yard or if it is for a splash of color, just a fat quarter.
Another hint when it comes to fat quarters, if you have a friend with similar tastes, buy a half yard and split it in the fold, 1 piece for each of you, it is much less expensive than the precut fat quarters. My friend and I do that each time we start another quilt together. We each make 2 of 6 of the blocks for a 12 block quilt and exchange them.