I just noticed this thread so I didn’t see everything that was already said, so pardon me if i’m being redundant.
Not every child can necessarily be the gadol hador, nor is that a goal at all. Gadol hador is a competitive title, meaning greater than other people. That has nothing to do with doing the ratzon Hashem and being an ehrlicher Yid. If you’re in it for the gaava of having a son that’s better than other people’s children, than you are approaching chinuch with a anti Torah hashkafa, and it will not bring good results. Remember the story of Acher? We are supposed to learn something from that story. The lesson is chinuch with motives which aren’t pure will bring bad results.
If you mean to ask a correct and appropriate question, then you should be asking ‘How can I raise my children to fulfill their potential to the most possible?’
The answer is give them lots and lots of love and positive reinforcement. Make sure they are always feeling good about themselves.
Excessive demands could ruin this so be careful. Very careful, more careful than you realize, because it is apparent from your question that you are heading for a disaster in this very area for this reason of making them feel inadequate. If chas vesholom they will feel inadequate and bad about themselves, they will fail for sure.