After somewhat learning at an empty Walmart, I took my trailer to a state park that's open all year. Hardly anyone there so you can find an empty loop. That was much better practice because you can deal with trees, the angle of the pad, site number posts, etc.
I sometimes wonder why in the world when there's a tree hugging one side, they place the marker post directly on other, leaving you a narrow margin to back into.
I was asked earlier this year by a gentlemen if he wanted me to have him back my trailer in. It was a very weird angle involving a pad off of a "Y". I told it that would be great, but I really need the practice. What I would really appreciate is him giving me direction. He was glad to do that, and I was glad to receive it.
Be the kind of woman that when your feet hit the floor each morning, the devil says, "Oh, crap. She's up."