I am using an old fashioned hem guide... the metal one with the slide to mark the length you want.. to measure my individual pieces to check seam accuracy. I feel like it is more precise and reliable than my cutting mat measures and my plastic rulers. I once bought a box of thread and other sewing doo-dads at a yard sale and in the box was about a dozen of those metal guides. Anyone want one? LOL, I have way more than I know what to do with.