Re: "Don't use strength!"
Something that might help....I was at a seminar with Ledyard sensei and he said something that has stuck with me since and helped me fix body position and ...relax:-). Make sure your arms are only moving up and down during the waza and remain on the center line of your body. Never let your arms push or pull laterally or stray from your center line. For example: ikkyo ura - many have a tendency to move faster than their uke and end up pulling them around. Instead, focus on cutting straight down your center line while you tenkan. Maybe you will have to move/enter a little deeper. I found this to be most helpful when trying to "relax" and use this when teaching my students....difficult to impart well with the written word... Good luck in your test. Show what you know - you don't need to be an expert - shodan is beginner level.