Consistent schedule for uploading/streaming.
Focus on quality content/retaining viewers
Collaborate with other content creators in the same genre
Don't sexually harass fans/don't send creepy or cringe dms
Keep your grades up.
Get half decent audio equipment. Doesn't need to be the most expensive (quality content can make up for this short-term but not for long)
Usually for earlier channels, it's easier to make better content with a partner/small group until you find your personality.
Titles and thumbnails matter more than you think.
Don't force it, but keep an eye out for clippable moments and share them where they would be relevant. Make sure to link the channel.
Or like... Sick people.