Be loud, unfunny, occasionally insult some other streamer but don't actually mean that, put a huge ass overlay on your screen, get a partnership with some big streaming network, and invest as much time as possible in that fuccboi look that makes the 13 yo females soaking wet, also pretend to be a huge pro player when you're just a gold-plat-diamond shitter that barely knows how to crawl out of laning phase, also pretend to be "toxic" but then reveal a sweet and emotional side later on, be a huge weeb (Naruto, SAO, Monogatari series, legend of korra), have a girlfriend that does cosplay and most important of all order on amazon some retro console even if you didn't touched a videogame until you were at least 16 because your nerd friend in high school that was actually very charismatic but never scored once because he was from a low-middle class family introduced one afternoon you to videogames.
Also play undertale, really important. And you have to enjoy the shit out of it even if it makes you puke and you wish you could rip off your eyes as you're playing it.
Time to bank in those juicy money kiddo. $_$