First look at the Confetti quilt. It will be twin sized, there is an additional row of length I couldn't fit into the shot. The sashing is on each left side of the blocks, need to determine layout and and make the long skinny sashing rows.
The juvenile novelty focus fabrics are 6.5" raw. I cut the confetti fabric at 2.5", it required ~2.5 yards. The sashing squares varied in length from 6-6.5", I cut them all 3" wide x length. In my project I used 35 focus fabrics set 5x7, it should measure 68x94". If you are doing the sashing by squares, you need two squares per focus fabric, plus one square for top/bottom sides (5+7 = 12), for a total of 82 squares in addition to the 35 focus fabrics.
In this case, I chose to highlight the novelty fabrics. Had I chosen to do floral centers, I could hide the novelty pieces in the sashing instead.
I made the deliberate decision to make all the lengths random to use the fabric I have, and therefore am setting the sashing randomly offset. I can see where if you wanted to be precise you could do something cool with a light/dark/woven pattern if you wanted. I just want to slap this together
You could do the same sort of thing with 2.5" squares for the sashing, in that case you might want to consider changing the confetti frame width to 1" finished instead of 2". Also, I think it would be a good way to use string or crumb quilting pieces in the sashing. The quilt we make depends on the scraps we have!