In you photo you show a strip of squares stitched together. From your description you are endeavoring to be accurate with your quarter inch seam. The real test comes when you stitch the rows together. Pressing of your strips is important. Be sure to press the seams so they oppose each other;then, they will nest together when you stitch them and the seams will be perfect. For instance, press the seams on one strip to the right and to the left on the next strip. Please be careful not to work too far ahead of yourself in case you need to go back and fix something-you don't want to have to fix a lot of something. I know about being a perfectionist because I am one and I will always go back and fix problems-I can't let it go and for that I make no apology. Keep up the good work and enjoy the process and build your skills one project at a time.