As a 18 wheel driver for 30 plus years I can tell you that longer is easier than shorter, however, practice makes perfect, or at least better. Slow and easy does it. Don't saw the steering wheel back and forth when backing .Imagine a line that you want the trailer tires to follow from where you start to where you want to end up. Another way to look at it is if you were pulling out of the space how would you do it? Then do it backwards. The only way to learn how to back a trailer is to do it. Parking lot practice is best. Drive in a spot straight, set up some cones, drive out go in a circle and and back in, set up the cones and do it again. You will learn to back up before you get dizzy. Also learn to back without a 2nd person guiding you.