Mordecai makes a very valid point. During the test, the examiner really doesn't want to hear you 'patter' through everything you are doing. It's a 'commercial' flight test, and so you wouldn't expect the captain of your aircraft to talk you through everything he's doing.
Structured hour building is the best idea. Take the PPL skills and hone them. It's not a black art, passing the CPL test, but smooth, accurate flying is what he's looking for. There are quite a few examiners who post on here so they'll tell you what they're looking for.
Another point for the test, if you fail a section early on, I know it's not easy to do this, but try to put it behind you and concentrate only on the next section. Aslo, i'm sure if you mess up somethig like a steep turn etc, I can't see why you couldn't say 'look, that was rubbish, can I try that again' Obviously time constraints might not allow this.
If you hour build, take an instructor or even an experienced pilot (CPL etc) Some of us are quite happy to go flying and give advice if wanted.
Just enjoy it. The worst part of the test is the walk back to the debrief. He won't give anything away until you're seated and going over the post flight debrief. Seems like forever. Good Luck.