honestly i think i got most of my followers from when i was a band blog and made edits. i think that posting your own content helps a lot with getting followers, while self promoting on other peoples art is kind of annoying and rude (being as it’s been done on my art)
i think if you post content that you really like, and has a fair sized fan base, you should get followers!
but also 300 people is like, a lot of people! you should proud of that already!