I have never been an examiner however, I was an instructor for a while and saw a variety of different attitudes and abilities from PPL to CPL level.
I think the key to this is a polished, slick, professional looking operation. You can do this with the way you interact with your instructor/examiner, making sure your planning is thorough, keeping your briefings concise and to the point, checklist discipline, thinking ahead and managing your time. If you can master and put all those things into your operation the flying is the easy part.
Adopting this attitude will work wonders for your future flying career through your learning and development in the flight deck.