When it comes to expert performance, we tend to think that those with the most experience will do better than the beginners. For example, we reassure beginning-level speakers that the more they speak, the better they will become.
However, according to Time.com article "The Science of Experience," it's not the amount of time spent repeating an activity that determines expert performance, but the time spent practicing the most difficult skills associated with that activity.
"Ericsson's primary finding is that rather than mere experience or even raw talent, it is dedicated, slogging, generally solitary exertion — repeatedly practicing the most difficult physical tasks for an athlete, repeatedly performing new and highly intricate computations for a mathematician — that leads to first-rate performance. And it should never get easier; if it does, you are coasting, not improving. Ericsson calls this exertion "deliberate practice," by which he means the kind of practice we hate, the kind that leads to failure and hair-pulling and fist-pounding. You like the Tuesday New York Times crossword? You have to tackle the Saturday one to be really good."
Keep practicing and keep speaking, but don't get too comfortable. Keep working on the aspects of public speaking (or your job or parenting or golf. . .) you find most difficult and frustrating. That's the practice that's going to raise your performance to expert level and keep you on track for success.
Thanks to Mindhacks for the heads up on this article.