I can't figure out how to insert a photo, I can't find the "insert image " icon, probably staring me in the face!
But I've made a gazillion I Spy quilts, I use 6 inch blocks (cut size so finished block 5.5 inch) 6 across, 8 down, and a 4 inch wide white border with the words "I Spy a dog" etc using animal or objects actually in the quilt, I separate each "I Spy a cat" or whatever by 1.5 inches. I use the decorative letter stitches on my machine, not the embroidery unit.
I also use the rick rack stitch to separate each block so the blocks don't just run together.
Where is that "insert image" icon?