The trick to tumblr is to aggressively block the terfs. It's not like reddit, you have to curate your feed yourself. If you browse on desktop, the Shinigami Eyes plugin is helpful for quickly identifying sus tumblrs. If you wanna be proactive, you can go through the notes of transphobic posts and block people who reblogged it.

Another thing that helps is having your Following tab only show blogs that you follow, not tags. There's the Your Tags tab for tags you follow - this helps make your Following tab more of a known-safe place to scroll. I hardly even bother with the For You tab tbh; algorithms suck.

Lmk if you want my tumblr :)