Dont count the things you do, do the things that count.
There has never been a statue erected to honor a critic.
Positive thinking will let you do everything better than negative thinking will.
You can literally force yourself to be courteous, happy and enthusiastic with every person you meet. After you have forced yourself to be so for a short period of time... the habit takes over.
The first step in solving a problem is to recognize that it does exist.
Never make a promise without a plan.