way I did it was to take 2 of the small squares and sew them together, press and then sew those to one side of the large square. Now take the last small square and sew it to the end of the rectangle. press and sew to first section as shown in pic above (top left corner is a good example). then once you get all your squares pieced you arrange them however you like and piece add borders and voila she's done.
it goes pretty fast once you get all your blocks done.
*edit* forgot to tell you use 1 of each color in each block. so each small square, rectangle and large square in each block will be different fabrics.
*Hopes I didn't confuse you more*