Luring a Rex into a taming box built on a raft is my favorite way to go. A Dino gate at one end and a ramp leading up with walls two high let's you tranq the Rex from a safe distance and you can transport the tame to a safer location than where other rexes spawn. Stone walls and foundations are a must. A good flyer is helpful as well.
I have figured out a new way to tame dinosaurs cut off the dinosaurs meat wise in the area try and keep the dinosaur in the area and send a dodo bird out to attack the tea Rex with bunches of Botox in and it had the tea Rex eat the Botox and it’ll knock it out you go feed it meet make sure you have plenty of Botox in and you’ll have a pet your ex and no I would not recommend trying this whenever your level one side effects may be dead dodo bird hey might find you and run but seriously You better find a good hiding spot