There are 3 types of backing:
Straight line - most preferred
Sight side - next preferred since you have a good view from the drivers window
Blind side - least prefer and what you describe. It is so problematic that some trucking companies forbid their drivers from performing a blind side back.
If you look on a truckers mirror you will often see a sticker "G.O.A.L." for get out and look. It's often the best method.
There is one CG we frequent that requires a blind side back but at least the sites tilt at a 30 degree angle to the road which helps. The swoop method works well but remember you won't "lose points" if you get out an look. My partners job is to sit on the picnic table and tell me when the sewer pipe lines up with the CG's connection and to watch clearance behind the trailer. Everything else is on me for the sake of our relationship and my sanity.
Good luck and practice makes perfect.