"Self-discipline begins with the mastery of your thoughts. If you don't control what you think, you can't control what you do. Simply, discipline enables you to think first and act afterward."
Brian Tracy defines self-discipline as "the ability to do what you know you should do when you don't feel like doing it." He explains that the two biggest enemies of self-discipline are taking the path of least resistance (ex. a get rich quick scheme) and instant gratification. Don't always act on impulse but weigh the possibilities first.
It may appear that some people have self-discipline and others don't. However, self-discipline is not an innate characteristic but a learned skill. Anyone can learn it. Forbes contributor Amy Morin suggests six ways to develop the habit (http://www.forbes.com/sites/amymorin/2014/10/03/6-ways-to-develop-the-self-discipline-necessary-to-reach-your-goals/#55a471b14fdb):
1. Acknowledge Your Weaknesses
Have you ever heard a smoker say "I could quit if I wanted to." More likely they are simply not admitting that they can't quit.
2. Develop a Plan
Outline the steps to reach your goal.
3. Remove the Temptations
If you can't resist spending, leave the credit card at home when you go to the mall.
4. Practice tolerating Emotional Discomfort
We all have to experience emotional discomfort at some point. Learn to tolerate boredom, frustration, loneliness and sadness.
5. Visualize the Long Term Rewards
Jack Canfield, while he was writing Chicken Soup for the Soul, visualized the title at the top of the bestseller list. Despite 144 rejections by publishers, he persevered.
6. Recover from Mistakes Effectively
Acknowledge your mistakes and move on with resolve to do better next time.
Note: For books about self-discipline, visit http://godlikediscipline.com/2016/01/21/37-of-the-best-books-for-increasing-your-willpower/.