Totally agree on the Tony Kern books - I own Flight Discipline and kick myself I never got it years ago!! Should be a must read for every PPL!!
Just wanted to say thanks for this info everyone - it's quite timely and handy for a current assignment of mine - very CRM and Human Factors-ish, involving communication but this 'judgement' stuff is useful too!
PPRuNe, the first place I go to research!