I saw this wonderful tip on another forum and just had to share.
When doing a panto and there are embroidery designs on the quilt, move the needle to the area, cut a piece of paper the size of the design and lay it on top of the panto to know to stop in that area. If it is a large design that covers two passes, just move the paper to the bottom on the second pass. If you have several different sizes of embroidery just cut a paper template of each section to cover your panto.