Make it a high priority to become a person who is consistently grateful. Let this be an important goal. "Nothing stands in the way of a strong will." This principle is the source of the success of successful people. Those who achieve excellence in any area need to have a strong will to take action.
If you are not yet a person who has mastered gratitude, intensify your will to do so. The stronger your will, the more likely you will succeed.
Studies show that people who make goals are much more successful at whatever they do than those who don't make goals. Without making a formal study of it, it appears quite obvious that there are many more people who make it their goal to make more money than there are people who have it as their goal to master gratitude. A person who has great wealth will still be unhappy if he hasn't also mastered gratitude.
(From Rabbi Zelig Pliskin's book: Thank You! Gratitude: Formulas, Stories, and Insights: Artscroll Publishers)