I would (and have) purchased 3 or 4 yards of the one that I love the most as my 'focus' fabric. Then I will pick 6-8 of the coordinating fabrics and buy a yard of each. And about 4 yards of the one that I think would be best as a backing. That usually keeps my covered on just about anything I design or pattern that I find. Although sometimes I end up switching my focus and my backing by the time I really use it.