Shoulders back, hold your head high, and like others said, own it. Being tall doesn't make you not pass, it just draws attention, and if your presentaiton doesn't blend, then you won't pass cuz they looked you up and down, which shorter women deal with less. 50% of passing is confidence, you have to project it. I am 6'2"ish, I get comments constantly about my height, but they are more like wow you're a tall lady, not wow you must be trans.