I was taught by an ex lorry driver, and often drive vans, so this isn’t what you will be taught by a driving instructor but I find it easier...
Don’t turn round, use your wing mirrors. (Don’t use interior mirror either)
So when you know you are going to have to reverse. Stop. And have a good look for anything behind you, bollards, posts, pedestrians etc. Turn in your seat, move your head around, have a GOOD look.
Once you have settled back in the seat, put it into reverse and look in one wing mirror then the other, see how the edges of the road line up with the back of the car, now creep backwards, look at one wing mirror then the other, a second or so for each, if the edge of the road is looming closer in one mirror than the other, correct it by steering (turn the top of the wheel away from that mirror) and keep on doing that..
You will probably overcorrect slighltl, so watch for the edge of the road in the opposite mirror and steer slightly away when you see it.
Every few seconds, slow down a little and check for other vehicles or pedestrians coming up behind you, and keep on doing that. When you see the lay-by steer gently into it.
If it’s tricky to get the car into the lay-by then keep reversing back past it, then drive forwards into it instead.
And don’t worry too much. I live on a road like that. Some ppl are bloody useless at reversing. As a local I kind of expect to be the one to back up, but I also recognise other locals cars, and some of them have NEVER learned to back up competently.