Build a taming pen. Walls should be doorframes. I suggest 2x6 and two high. Put a hatch frame as the ceiling. Lie down near the whole on the hatch frame ceiling and feed him as needed. Boring, but efficient. I use my normal taming pen and just add the other walls as he walks around, to box him in on one foundation. Then, I remove the walls when done.
I've found him every time walking along the beach of the redwood biome. What was mentioned earlier works, build a stone trap. One foundation 4 door frames get him to chase you in then seal it. A random sabertooth tiger showed up during my tame attacked him and reset my timer, so beware.
The kibble for these guys are a real pain to get but there is a way to get the Titan boa eggs to spawn for you. First you must have a argent or quetzal , 2nd you have to build a large pin in the swamp biome about 6 foundations wide and about 40 foundations long. Put a dino gate in the middle of the pin and make all the walls that have windows in them (use gate foundations to place the walls on the outer perimeter) and I made the pin half on water ,half on land. 3rd step is to use the argent or quetzal to grab Titan bias and drop them into the pin. Put about 10-20 Titans in the pin and fly away and come back after a few minutes. The eggs will spawn on the ground so get Argo and have them follow your flyer to once side of the pin. Then simply fly to the side where the eggs are and close the middle Dino gate on the way. It works and was the only way I was able to get Titan eggs. Perfect tame gigantopithecus are super strong and are able to solo any cave. The taming is really fast.
Use ghillie armour to feed him. Dont walk too close to them or they will hit you and you will lose your taming progress. Just give them space. Another good way to tame them is to make them mad and lock them up in a cage 1x1 with a hatch as roof then get him in there and get in the roof and feed him!