If it's a good backing fabric I usually buy 4-5 yds. I can always add the leftovers to my stash. If I just like it 1-2 yds. If I haven't spent a fortune that month 2-3 yds. If a white on white or ecru filler as much as I can afford at that particular time. My husband is always on my case to use what I have. He just doesn't get it. lol
Sue