Make sure you're as loud as you can when doing a let's play. Use a green screen to capture the crowd's attention, and always collab with the popular stars and never the scrubs.
Make sure you dye your hair, and I'm not talking about black or brown, I'm talking about a color that makes you pop. Be ready to spend a lot of money because to make money ya gotta spend it. "How much money should I spend?" Enough to make you popular. As the saying always goes, money talks.
Make sure you use an actual camera and not your phone. If you must use your phone, for god's sake record it horizontally and not look like you're using a potato. Be as loud as possible to draw the audience's attention. Make sure you give your subscribers a cool nickname, and give yourself a cool nickname. Cool nicknames equals more views, no nicknames equals less views.
Make are to cause drama and controversy because that equals more views. Constantly advertise yourself to your peers and family. Again, make sure you're as loud as possible and funny too.
"But.."
What! What could possibly be more important right now?!
" I'm doing this for a school project."
Oh. Well okay, then this changes some things. Alright, let's take it from the top.
Step 1: Don't record vertical, and for god's sake, don't record like you're using a damn potato.
Alright, with that little bit out of the way time to get a bit more serious. Honestly, to be a good YouTuber, it's all about the time and commitment you put into your work. Take a small YouTuber such as The Thriving Artist. Just by looking at her work, its pretty obvious to see that she puts effort into each video she makes, from script writing to video editing. For a small upcoming channel to already have almost 300 subscribers is really something else. All of this is coming from the time she's invested into her channel. As cliche as it sounds, to have a successful channel, it all comes from how much you work toward it. Plain and simple.