I have seen a ponytail plant whose leaves are very curly. How does this happen..can I make it happen to mine?

I'm afraid you can't make it happen to yours - the plant you have is likely to be Beaucarnea recurvata, also known as Nolina recurvata. It has straight leaves and is from Mexico.

The ponytail palm with curly leaves is Beaucarnea Guatemalensis and the young leaves often come out red before turning green later, hence another name given to it is the Red Ponytail palm. It comes from Guatemala.