We've used the same technique for years and you are correct that the key is to get the boat moving. I will also note that when we switch from forward to reverse, we use significant throttle to stop any remaining forward motion and to get the boat moving in reverse. My wife has a tendency to forget to throttle up when in reverse, so I gently remind her beforehand that idling in reverse is useless.
Another tip is to make sure that the engine is in neutral before switching to reverse. Shifting directly from forward to reverse can kill a transmission. We coast parallel to the slip and while making the 90 deg turn to back in, bleeding off forward speed. Only when we're lined up with the slip (offset to starboard 1/2 boat width to account for prop walk) do we put the boat into reverse.
I do not like to stand in front of the wheel facing aft because then all the engine controls are reversed and it's hard for me to reach the shifter and throttle. I prefer to face forward and look over my shoulder. Just remember to turn the wheel in the direction that you want the stern to go. For tillers, point the aft end of the tiller where you want the stern to go. It's that easy.
Sabre 38 "Victoria"