As someone who’s been around since the early days of hololive. The absolute best things you can do for exposure is create good fan content.
Fanart, memes, and most of all clips. Make short clips that are quick and easy to get peoples attention.
Fan content which is rampant in holostars fandom but does ABSOLUTELY nothing to help your oshi:
>porn, and not just because it’s hidden /here/ or in locked Twitter accounts, but because you can’t share it
>handmade cutesy yume goods, unless you’re in a physical space like a con or a live, useless as online fan content
>not leaving a comment after watching something but just chatting here or in discord - LEAVE A COMMENT
A lot of this is the way people have fun and it’s totally fine, the most important thing is to have fun and consume things how you want to, but if you really want to help as a fan and show support, you need to be proactive and not passive, and actually make stuff that isn’t just in fangirl mode. Ie make animations, art, videos and clips. If you’re a translator or want to summarise info about your oshi, make it available to the public instead of on discord or /here/