Backing...take your sweet time, GOAL - get out and look, gentle maneuvers, practice! Repeat & repeat. Don't let it whip ya...
From my understanding it is not always half way. Find the sweet spot on the rig you will be testing in. That's the important thing. On the road with your trainer you can learn about floating if you want to learn it.
Something to help you get over the nervousness of trying to impress the tester is just remember that probably 90% of the testers have never driven a truck and could not do better than you can. Back in the early 90’s I had a lady ride with me and also tested a friend of mine the same day that said she never drove a stick in a car. Think about it cop cars have all been auto’s for 50 years and that includes the Dot man’s cruiser too.
Buddy I’ve been there not that long ago and it’s okay to be nervous; what’s not okay is not stepping up to the plate and accepting the challenge, good luck and you’ll do fine