Practice doesn't make perfect

More than practice is needed to perfect skills. In a study of a computer game (Axon), some players with the same amount of practice ended up performing better than others. Surprisingly, those that ended up performing better included players who (1) spaced out their practice or (2) performed inconsistently at the beginning. According to Tom Stafford of the psychology department at the University of Sheffield,

People who were inconsistent at the beginning of play performed better later on. This was surprising, but our theory is that this inconsistency doesn't reflect flakiness, it reflects a willingness to explore the parameters of the game. But being unafraid to fail early on, you can gain the knowledge needed to support superior performance later on.

In other words, not just making mistakes but learning from one's mistakes improves performance.