Alright, so I've been posting on BookTok for about a year now, and I've tracked my analytics religiously. The absolute non-negotiable for me are #booktok and #bookrecommendations. They're the big, broad buckets. But honestly, the real growth came when I started niching down.
My most successful videos always paired a broad tag with something super specific. Like, if I'm talking about a fantasy romance, I'll use #booktok but then also #fantasyromancebooks and maybe #enemiestolovers if that's the trope. The trope tags are gold because people actively search for them when they're in a mood.
Don't forget to tag the actual book title and author with the '@' mention if you can, especially for newer or midlist authors. Their fans will sometimes search by name and boost your video. I also throw in #readingvlog or #bookhaul for casual browsing vibes, depending on the content.
My weird little hack? I always include one slightly offbeat tag related to the vibe, like #cottagecorebooks for a cozy fantasy or #morallygrey for a dark academia novel. It seems to catch the algorithm's eye and connect with smaller, dedicated communities.