Beautiful! I do like the idea of sashing between them, it would frame them all nicely. Maybe a soft solid color that looks nice with the cross stitch blocks. Maybe the green, or lavender. It would give it a vintage look. You may just have to take several blocks to the LQS and lay them on some samples. I was originally thinking a small calico, but that may be too busy...you will just have to go and look for something that you love and that makes those blocks POP! You will find something that strikes your fancy!