I heard the idea of the 3x5 card on the 15 Minutes of Mental Toughness Podcast the other day. The host, Dr. Rob Bell had one of my favorite Leadership role models - David Novak on as a guest. David is the former CEO of Yum Brands, and I have read a number of his books and religiously listen to his Podcast "How Leaders Lead".
David spoke about how at the beginning of each year he uses a 3x5 card (actually a 4x6) as a self awareness exercise. On the card, he writes:
What am I today?
How can I be more effective tomorrow?
He said it is significant that he used the word "and" instead of "but" because it shows that you have done a lot to be effective already and that there is always room to grow.