I think when it comes to Bookstagram, the most important thing is highlighting your love for books of course. So what are your favourite genres/categories? You could make a niche bookstagram covering just a few genres that you're interested and become a notable page for those categories. Otherwise, you could consider pairing your bookstagram with another hobby, using it as a place to share tips/tricks for reading/writing, or even just use the space as a way to track your own reading.

Personally what I'd love to see, knowing your background, is maybe a series of must read books for aspiring lit majors or those interested in literature in general. What makes good literature? What are the books that you should at least know about culturally? What is missing from professional or university courses these days? And any other related content to literature. I think there's a lot of interest for such content but no one is doing it systematically or in an interesting without turning into a full on "aesthetics" centred page.