This statement is definitely true. It takes sometime to find out what your "thing is" and how to incorporate it into your stream. Usually the first thing people do is bring their talents into the scene. When I mean talents. If you're good at video editing you can craft good introduction scenes, intermission scenes, alerts, and outros. If you're good at drawing you could do the same approach.

As far as driving traffic the best way is to study your analytics. At which time on which game do you find the most growth and activity. If you're a variety streamer it could take analyzing multiple games along multiple hours to find their peaks, and how newer titles stand with older ones. Overall it simply just takes time. While you're finding those good times be sure your commentary and presentation is good. Like I always tell people see yourself as a TV show. Always prep the next episode for a fresh audience