Make little number tags (or use an old calendar page) to pin to the first piece of every row. I take the rows down off the design wall in a stack from top to bottom since that is the way I designed the quilt.
You will be sewing 2 rows at a time and this is the way they need to lay, to the right of your machine. Why to the right? Because if you lay them to the left they will eventually be knocked on the floor by your work in progress.
The uneven numbered rows (1,3,5 etc.) will always be at the top and even numbered rows (2,4,6 etc.) will be on the bottom (as in the photo above). Pick up the first 2 pieces from row 1 and sew. Pick up the first 2 pieces from row 2 and sew. Don't take them off your machine.
Sew piece 3 onto row 2. Continue in this manner until all of the pieces are sewn in the 2 rows. Your tags are on the first piece so you will always know which row you are working on. Seams should be pressed up on uneven numbered rows and down on even numbered rows. When sewing the rows together there will be one seam that matches about every10" so you can pin at those spots if you are a pinner.
This photo was taken before I took all of the rows off the design wall. This one has 20 rows across and equal to 29 squares down so it will end up 40" x 58". You can make it any size you want. It doesn't matter if it is an even number of rows across or down. I was done when I ran out of 2.5" strips in the box. You might have a better plan.