I do a lot of 6" squares quilts for charity. For Lutheran World Relief, the specifications are 60" x 80". I do 4-patch blocks, then sew those blocks into 6 colums of 8 blocks. Finally sew the columns together. It works for me. BTW for those utilitarian quilts, I use 1/2" seams. If I choose to make a border, it is 6" also, and then the situation calls for 5 columns of 7 blocks (all 4-patches).
These quilts are worked up quickly because of the 6" x 24" ruler.
Dayle