I sew strips 1 and 2 and stop. Next I then sew 3 and 4 and stop.
Next sew those two sewn strips together to make a group of four sewn together strips and stop.
Next sew 5 and 6 together stop. Next 7 and 8, and then sew those sets together into the next group of four sewn together strips.
Keep sewing strips of fours until you have enough.
Now sew all the fours together and add any additional strips to make the count right....They should lie flat!
It is OK to Iron them....