My friend, who works for Accenture, told me that creating an elevator pitch for himself was one of that training programs that Accenture put him through, as part of his on-boarding program. The program, he said, was aimed at experienced hires. More importantly the training was a workshop where he was required to create the pitch as part of the program. It was learning by doing. He also mentioned the he watched others pitch themselves and fine-tuned his pitch based on the techniques of others. It is evident that learning by doing works, even for those with decades of experience behind them.
I also, believe it is easier to unlearn old habits when you learn by doing.