Stream to twitch only, that way you don't have a split audience. You'll have everyone on one site, thus having more viewers to get noticed on twitch.
Play a game new viewers can get invested In. Something with a story and isn't repetitive like online battle field. After a while whatching someone play the same maps over and over gets boring, then people get won't watch any more. Instead play something like dark souls or something you can level your character and do new stuff or quests every time you play.
Or play a game that is popular at the moment, that way more people watch.
Just my two cents. Good luck!