The pieces for the quarter-circle blocks were cut using acrylic templates that my husband was willing to make for me.
To begin with, I cut 4" squares, and then marked the profile of each template on the squares. This approach seemed to speed up the cutting process.
I then assembled the blocks by just ensuring that the two pieces were different colors. One of the most helpful tools to have handy when sewing curves is a pair of blunt tweezers to help pull the final bit of the fabric around the bend as it approaches the feed dogs on the sewing machine.