I forgot to tell you I also marked a line on each piece for that size square.
example: a line at 7 1/2 inches on that strip will give me my 7 ' square after sewing.
Then I marked with sharpie the center of each square (+) so when triming I can center the block underneath trim 3 sides then turn it around and line it up and trim the 4th side.
No more loop sided or uncentered squares for me