Most of my hems I do "by eye," thus the "lazy" method.
First, I press up a hem.
With the hem pressed, I bring the item to the CS machine and place it raw edge side UP under the needles so that the left-most needle is just at the inside of the raw edge. Most of the time my edge does not line up right next to one of the guidelines because those guidelines are more regularly incremental than my "by eye" amount.
So, out comes my handy-dandy "hem guide." Yes, a little pad of Post-It notes. (Thanks to a PR member for this tip.) I butt it up next to the folded edge and press down so the whole pad is temporarily stuck in place.
Then I turn the fabric over so the wrong side is facing down and I'm ready to start stitching.
Voila! The underside of the hem is encased in coverstitching with no raw edges to trim. (Please pardon the stitch quality of the off-grain hastily made sample.)