Thanks everyone - glad you like it! The pattern is a riff off something I saw in a magazine - I don't recall the name of it. But here's how I did it; VERY simple and fast.
Cut 4 1/2" and 2 1/2" squares.
Sew a small square to opposite corners of the large one, diagonally, so it makes a HST. Cut off the excess fabric underneath and press open - sort of like making a snowball block, but only on two corners.
Then when I sewed the blocks together, I arranged them so the small HSTs (in the light blue fly fabric) formed a square.
After that, I wanted to enlarge it and add a border, so I sewed strips of the uglies all around, like piano keys, and voila.