About Miller Performance Coaching . Millers Performance Coaching is a Sydney based business specialising in Mental Skill Conditioning Coaching for Sporting or Corporate Clients world wide. Millers Performance Coaching has been associated with coaching professional coaches, athletes and teams for over twenty years. What Miller Performance Coaching has achieved. Miller Performance Coaching has been fortunate enough to work with members of the 2010 Winning Americas Cup Team, Australian Rowing Team , Australian Sailing Team ,NSW Cricket Team and a number of corporate companies just to name a few.