I drive a rear blind vehicle a full size conversion van. When I back up I do two things. I put on my back up lights then look as good as I can in the mirrors and turning my head. I give a couple short taps on the horn and back on out slowly. In 30 years of driving mostly conversion vans I have not had any problems. Generally though I'd rather back in and pull out if at all possible. Backing in you have a fresh look before backing up.
I have a nice scrape on my rear bumper from an idiot who tried to do just that.