Thanks for this tip! I like working block by block instead of the long row of skinny sashing, trying to line up the cornerstones.
The sashings are scrappy on this quilt, so I wanted to keep my sashings in order after placing them. I chain pieced the first sashing to the block, then the cornerstone to the second sashing, then the second block with its first sashing, then its next sashing is joined to the cornerstone, etc. to the end of the row.
Without clipping the chain apart, I pressed the seams. Then as I clipped them apart, I pinned the second sashing/cornerstone combo for sewing and stacked the blocks in order for joining.
On this quilt I join the rows as I go so I can see what scraps look best as I progress to the next row.