The one mistake that I made when buying stash was purchasing too many focus fabrics and not nearly enough of the quieter blender type fabrics (tone on tone, mottled or marbled). As a result, I had a lot of fabrics that were very pretty or interesting but didn't go with anything. I also bought too many dark or intense colours and very few lights with no plan for their use. I ended up with a lot of fabric but less would have worked if I had known exactly what to buy. I'd advise only buying that wow fabric when you have a specific quilt and yardage requirements in place. For your stash I'd buy mottly or marbled or small print fabric (1 yard cuts)in all the colours plus some tone on tone cream, white and black for backgrounds. Buy the wow as needed and pull the co-ordinating fabrics and background from your stash.