Don't set accomplishments too far above a person's ability. People do not attempt to succeed if they believe they cannot succeed, or if they fail to see the value of striving hard to succeed. Role play, case studies, drills, etc., can all be of help. Ignore mistakes but praise good points and progress. Behavioral change comes about through increasing one's strengths, through a confidence-building process.
Weaknesses then fade from the picture.
This avoids a fault-finding environment. Coaching is an endless task. Not completed after one month or year. Later, send the person to take courses. Bad habits change only after much education.