Thosa siggt blocks are done by hand or machine, it depends on you. No matter. But it takes only a few minutes if done by machine. As for the central area, ya can even write anything fun, or draw any picture, image what you want... either you can make any applique cute and tiny to place in the center. Use your creative mind and feel free how it to be the best on your own way.
Have a great day,
Nihal