Originally Posted by BlueChicken

If you trim the larger blocks, you'll lose some of your points.

It would be easier to cut your sashing slightly wider. (the solid colour between the blocks)

Attach your sashing, then trim the blocks to a uniform size. That way, you don't lose your points, and a quarter of an inch difference between one sash and the next won't be noticed from the back of a galloping horse. ;-)