If the fabric design is a feature - not just random flowers or geometric prints - then I do. I did it for duckies and monkeys on a 9-patch baby quilt and it was adorable - every center square had a ducky doing something cute. But it took a while to figure out how to cut it without too much waste.
I also did it for a 'big-print' quilt where it was gorgeous floral Mary Koval fabric and it really made a difference - each big square on point had the same floral bouquet.
I just save the scraps along with any other leftover fabric from making the quilt and put all in one bag for 'someday'.