Jinkster, good luck with the test, when is it?
When I did mine (ok, it was 20 odd years ago) I was not told until I arrived for the test what the subject would be for the long brief & flight test so all subjects were prepared fully.
It was effects of controls so not too bad. I then had the choice of subject for a couple of short pre flight briefs following the long one (stalling & PFL).
We practiced (repeatedly) during the course using a whiteboard in preparation for the test & I still refer to my original notes - copied from the FI Instructors notes, copied from his F...... etc.
I found the initial (and first few renewals) stressful, so sought advice and hints as you have.
All the best.