So, every time after he had finished his interview, I gave him a letter written by myself and one piece of sticker. I usually praised him for his effort he has paid and his respect to the interviews/interviewers. I hope he can learn that "process" is more important than "result".
many good sharing and suggestions here! I will for sure have a trip during Christmas as I need to relax a bit! For the kid, I will take him out for a day trip to award his effort of doing his best during the last 2 months.