There's a slight delay of throttle vs speed, so my challenge was trying to predict how far to back off or push the throttle. initially I was doing the yo yo with the pole even with slight throttle movements, but eventually I was able to predict the movements.
Remember, when approaching the tanker you are faster, and most likely out of trim for the tanker speed, so re-trimming at pre-contact position is essential. If everything is perfect, trim, speed, flying the picture, you shouldn't need to adjust anything, but of course, it's never perfect. Something to shoot for, though. :)