I think it depends how you want it to look. If you want the lattice look,but larger, keep going like the layout you have, adding more to it mixing them up. If you want it with sashing and cornerstones, it would look like the link I added here. I really like your fabrics.

https://www.connectingthreads.com/bi...nload/p/991621

Another thanks to all of you for your thoughtful suggestions. As I said in my first post, I was inspired by a presentation Barbara Black did at the Long Beach Quikt Festival on Work Faster Nit Harder. For those interested, here is the sample she showed at that time: https://bbquiltmaker.blogspot.com/se...bel/X%20blocks
3” blocks set 4 x 6.

SuzSLO, I love those subtle blues and greens. I almost bought some of this line (but managed to resist). It doesn't look matchy-matchy at all, and personally, I would hesitate to bring other colors in and spoil the effect of these lovely shades. I checked the photo of the quilt with sashing, and I like this lattice look more, if you don't mind the effort of matching the x's. You could probably find more of these fabrics if you wanted to invest the money and time to make it bigger, but it would be lovely sewn and bound as. is.

Hmmm....looking at Barbara Black's quilt, her X's are all made from the same fabric and she carried that on by alternating each X block with a plain block. I like her layout because her X blocks really stand out and her quilt does not look at all busy. Using a single fabric for alternate blocks would definitely enlarge your quilt but personally, I would have difficulty choosing that fabric.

I agree that it's not matchy matchy. I am getting ready to make this very block for a juvenile quilt as well. My sashing will be all the same so that will definitely change the look of it as will sashing. My vote is no sashing. I think the X's will line up just fine when you sew your blocks together.