Before I stitch a pantograph, I move the machine across like I'm quilting the quilt, but don't turn the machine on. Just follow the design with the machine all the way across. By the time I get all the way across, I've usually got it figured out pretty good.
Remember to plan how you will end. I tape a ruler across the pantograph where the quilt will end. Then I have a vinyl strip that goes over the panto so I can draw on it, any changes I want to make with a dry erase marker. Sometimes I want to add arrows, so I don't get confused about which direction I'm going.
http://www.designsbyvickie.com/ has a lot of free designs.