Personality is a very wide term there are a lot of things which come under personality. to develop this you need to break it down into what aspects you want your child to improve. Example, If you feel your child finds it difficult to speak in front of people confidently then you need to work on his public speaking skills. Once this is done tackle another aspect and so on.
Gradually you will be able to see the development of your child personality. If it is not possible for you to work with your child on any aspect. We have a lot of programs that surely cater to all your child needs.