I'm making a twin sisters quilt for my son and his new bride. I started it a few months ago and cut it with the directions given with 2 1/2 inch strips. You sew them together, cut in half and then half again and sew the opposite strips together and it forms a 5 1/2 inch square. Yikes - way too small for me. What would be a good size to cut the strips, 3 1/2 inch strips, 4 1/2, any suggestions? Thanks!