Tell a child, a husband or an employee that he is stupid or dumb at a certain thing, that he has no gift for it, and that he is doing it all wrong and you have destroyed almost every incentive to try to improve. But use the opposite technique, be liberal with encouragement; make the thing seem easy to do, let the other person know that you have faith in his ability to do it, that he has an undeveloped flair for it - and he will practice until the dawn comes in at the window in order to excel.
Dale CarnegieWhen we are not engaged in thinking about some definite problem, we usually spend about 95 percent of our time thinking about ourselves. Now, if we stop thinking about ourselves for a while and begin to think of the other person's good points, we won't have to resort to flattery so cheap and false that it can be spotted almost before it is out of the mouth.
Dale Carnegie