Instead of sewing the rows together I sewed the columns down and joined them into four sections of 2 by 10 blocks (so 20 blocks total for each section).
I usually use cotton batting or 80/20 batting. It came on a roll so I just needed to unroll it to the length of my column and cut, so much easier.
Because I wanted to disguise my quilt as you go joining lines that I was going to do by machine I decided to do straight line quilting with my walking foot at fairly large intervals.
Once all four sections were quilted and trimmed (see above) I pinned back the batting and backing with straight pins and joined the middle two sections first.