One thing that has helped me when backing up without a spotter, is that I have three large bright red rubber flexible cones (about 2 ft. tall) that I will place at the back of the spot that I want to back into.
Since my rear camera will adjust, I put it at the 'hitch view' and put a cone at the middle at the end of the spot I'm trying to back into. The other two go 5 ft. on either side of that centered red cone.
I have no problem getting out two or three times to MAKE SURE that I'm doing it right. This cone set-up has really helped me. I now feel confident backing up because I can see my ultimate ending spot with the cones.
I know anything can happen so I try to minimize that as much as possible.
Quick story, I was traveling from Florida to Georgia and put the campgrounds address in my Nav. I accidentally put in NE 45th Ave. instead of NW 45th Ave at the beginning of the street name.
The Nav took me down a heavily treed fairly narrow country road. Once I made my turn, I realized that something was wrong and there was NO WHERE to turn around the big-rig. Finally, I see a fairly wide driveway on my right that had 'entrance fencing' but it still looked doable. It just so happens that the owner was pulling out as I was driving down the road very slowly. I waved him to stop and got out to ask directions, that's when I realized my error.
I asked him if it was OK to turn around in his driveway, he said "sure". So, I unhook the Honda, park it to the side with the flashers on. I pull past the driveway so that I can then reverse into his driveway. I pull out my three red cones putting one at the mailbox and the other two at the point where the entrance fencing narrows. That way, I could see the narrow points better.
Shockingly, I just fit without an inch to spare. As I was backing in, the front of the coach was swinging towards the fence across the street from this driveway. My front bumper was so close to the fence that a person could not have walked between the bumper and the fence. It was just enough room for me to complete my turn. I was lucky. The cones helped tremendously as I had no one to help me.
Safe travels,
MM.