What I do when there is no backer present:
Set out a wheel chock BEFORE you unhook the chipper. Hopefully your chock has a rope attached. Set it right behind the driver's side tire on the chip truck, and lead the rope up the side of the tire towards the front of the truck.
After you unhook and drive away, the chock lays right along side where you have to go next time. The rope helps make an "L" shape to fit into with the back tire.
With a little practice, this method can works faster than a n00b backer who makes you pull up three times.