I have a weird way I do it but it works so I keep at it:
I back up until I get in the ball park, then I get out and take a look and estimate about how far I have to go and in what direction, then I get back in the truck leave the drivers door open and put my toe fixed on the ground outside and begin to slowly back up look at my foot, you can actually see (and feel) how far the truck has moved and the direction very accurately when you are looking at a fixed point. When feel I have moved the estimated amount and direction I stop, usually I can just nudge and drop her down on the ball. I normally do everything alone so I don't have the luxury of someone standing back there.
Also, rear view cameras are cheating! Besides anyone who has them has WAY to much money and we should tax the hell out of them
