Pipergirl...while a I don't disagree that you need to put in a lot of hard work and effort into the CPL course (or any commercial flying for that matter) I do still believe the CPL to be the PPL's 'bigger brother' should we say?
In the practical sense, there is very little in the CPL course that you have not already experienced in previous VFR flying at PPL standard. Fair enough, a lot of the training is conducted in a 'complex aircraft,' however for PA28 flyers out there the Arrow isn't a million miles away from what you have been used to (assuming your CPL training is in a SEP).
In my humble opinion the key to it is concentrating on doing things a lot more accurately and smoothly than you had done before. The examiner is looking for a thought out, tried and tested procedure to be put in place for everything. I found my training to be based around demonstrating these procedures and applying them to the skills that I already had, or thought I had. The end product is a professional approach to your thinking and flying - this is what is being assessed in my opinion.
Best of luck
CK