For the I-Spy, I am going to add sashing to each square, then offset the rows.
In the Rainbow swap, we traded 11 squares of each color, and everyone received two sets per color. I am taking each set, and laying them out from light to dark. The second set is a reverse (dark to light), so I will have gradients of each color: red-orange-yellow-green-blue-violet. In this picture I have sewn the blue squares together.
And just for grins, here's my little princess doing a silly dance after jumping off the diving board.