I've been working on another project that involves chain piecing. This is using nickel blocks (5x5) and making a 4 x 4 set of blocks. This will work for any chain of blocks, I use this method when I'm stitching big blocks together.
First one has to decide how they want to place their blocks. If you are working with a lot of different prints, you may just decide to pull your blocks out of a paper bag. Or you can divide your blocks in darks and lights and alternate them. Or do an even number of big units of all darks or all lights. These methods is about as simple as it can be, and look great.
So after you have tested your seam measurement, just join two blocks together, only take a couple stitches without lifting the pressure foot or cutting your thread stitch the next two blocks, and repeat until you have stitched four roses of these blocks. At the end of that row just cut your thread ....no back stitching! Then at the top of that chain of blocks and chain stitching add another block, repeat with the next row. Now you have a dangly set of 16 nickel squares sewn together. Press your seams with one row all the seams going the same direction and alternate the next. This will keep the bulk down in the seams at the joins.
Now just take 2 rows and pin at the corner of each block...I go straight down in the seam to be sure I'm at the same place in the under block. Sew up those open seams in one long strip of 4 blocks. (This will be 3 seams). Press, and you have one block complete. I think you should have an 18.5" block. This what you would measure for center focus fabric. We will discuss sashing later.
In this last step in sewing the blocks together, hopefully all your seams on top are pressed upward, and on the underside they face downward. This will make a nice flat corner. It also helps your seams match better. That pressure foot just find of pushes one seam up to the other.