Self-efficacy is the belief in one's ability to succeed in specific situations or accomplish a task [Bandura, 1977]. It is like self-esteem, but rather than a general feeling of goodwill towards oneself, positive thoughts are directed at a specific situation or task.
Self-efficacy is correlated with many types of positive performance. This means the belief you are good at something actually makes you better at it! You may not be a kick-ass writer, but if you think you are, you will at least be somewhat better than had you thought otherwise. This correlation is also found to be true in creative tasks. Those people who think they are more creative tend to have higher creativity scores when tested [Tierney & Farmer, 2002].
So remember how we said that the first step to being more creative is understanding what creativity is? Well, self-efficacy is the missing link. If you understand that creativity is not being the next Michelangelo, but can even be incremental improvements to improve the usability of an object than you are more likely to believe you are creative, thus making you more creative!