OBW= One Block Wonder. I have made several SNW and OBW quilts and I am always amazed at what I get. Large florals do work up nice. You want to look for fabric with a repeat of AT LEAST 6.5 inches. I look for fabrics that are about 75% print 25% background. The florals always work but your block centers will still look like floral. More geometric designs really pop. If you are doing the OBW, I always buy enough of the focus fabric to use for backing. When I show people the original fabric they are blown away.