I have only occasionally talked about books on singing, etc. on this blog, but I am starting to reread one that is excellent, and is particularly germane to the purpose of this blog.
A soprano on her head by Eloise Ristad is really good. Unfortunately, I believe the author passed away some years ago, and I frankly don't know if its still in print, but if you can find a copy, snatch it.
It is all about throwing out the box you might find yourself in to find a new way to approach performing - of course, this is doubly appropriate for auditioning, where the nervousness can be kicked up a notch from a public performance. The title of the book refers to a soprano who was having a mental block on a Mozart aria, and the author's way of opening things up, was to have her sing it while standing on her head. The very bizarre nature of that act caused her to look at the aria in a completely different way - literally and figuratively!
I hope you can find this little book, but even if you can't, try breaking the mold you may find yourself in on any given aria.
For instance -
Sing a slow aria quickly
Sing loud passages quietly
sing a static piece walking backward
sing a passage where you have a mental block on text with the stereo blaring to focus your concentration in a different way
You see my point...none of the above deals with technique or diction, or staging, but it does have to do with shaking up your viewpoint, which can aid mightily with technique, etc....
Try it....and look for that book!