I use the 6 X 24 inch ruler every time I cut strips of fabric for a quilt top. I also use the 12 1/2 X 12 1/2 square up ruler to square up my blocks before sewing my rows together,
couldn't sew without them. Also have a 6 X 6 I use to trim and square up smaller pieces as I piece a block and a 6 X 12 for when I sub cut pieces from strips.