How to tame better giga:

1. Just trap it with simple giga trap then leave render or rejoin.

(rejoin only on SP)

2. Baby rexs, spinos and gigas will give it instant trust, so kill ur baby rexs, spinos and gigas and feed it to the carchar

3. When trust bar is at full, ride it and kill as many creatures as you can. (rare flower recommended)

4. You will instantly dismount when tame bar is at full so then you have a better giga. (Will still get nerf tho)

Btw saddle is unlocked at same level as giga saddle (lvl 96)