Ultimately, nothing will replace practice and experience. The suggestion to go out to an empty parking lot (think school, church etc) and practice a few times is a very good one.
Then just take your time your first trip out-and you'll get it. I think the initial anxiety can be worse than the actual experience. We have FT'ed now for five years, move probably an average of once a week or so, especially in the summer.
And the one thing that I think you can almost bank on (or at least I've found I
can) no matter how many times I do it. There will be that one time in 10 or so that it won't go in the way it's supposed to with out multiple adjustments. There is usually a direct correlation to the number of people standing out watching me.
These are the times to remember to take a deep breath, don't get excited, and know you will get there. I usually use this opportunity to get out of the truck, calmly and deliberetly walk around the back of the rig--look as if I have been making those adjustments in order to get it just EXACTLY where I want it, make motions with my hands a little to indicate I have decided it would be better just a little this way or that, then get back in and try again. LOL