Better known as backing on your "blind" side. If your right hand mirror says, "objects may appear closer than they" ...good luck! Distorts distance to much.
But at least you're not blind siding against one way traffic into a alley.
To get new hires more comfortable with blind siding, we used to hose down the spot they are leaving from, then have them pull out the trailer. Then put down some rope following the curve of the tire tracks, (where the wheels left tire tracks in the water). Then go around the block and then have them back up trying to keep trailer tires on the rope.
But first get some "stick" time as others have mentioned.
One of the first things I would do is (being careful) is see how sharp of an angle I can cut trailer to see if it will hit cab.
And daylight is more user friendly than in the dark.