Ensure that your candidate keeps promises he makes and finishes a job once begun, without leaving loose ends. Evaluate it after every assignment or project.
Practise defining goals in a SMART (Specific, Measurable, Attainable, Realistic, Timely) way with your candidate.
Ensure your candidate sets his own goals which he will practise to attain. Ask for feedback which goals are attained and which are not. What are the reasons for (lack of) success?
Ask your candidate to write down motives that help attaining a certain goal and motives that get in the way. Encourage him to find a way to deal with hindering motives constructively.
Ask the candidate to reflect on a situation in which he controlled progress well and one in which he could do better in that respect. What were the differences in context? Think about people, tasks, resistance, interests, time factors, et cetera. What does the candidate learn from these situations?