What I want to know is "How do you freely tell people you're gifted or have a high IQ in a way that is entirely neutral?"

Not sure why you ignored my original example. As I said, you tell them that you are good at something that implies high IQ score, but is not perceived as status seeking. "Hi, I'm Joe and the main thing I'm good at is art." is not the same as "I draw better than 99.9998% of all people", which would be the equivalent of "my IQ is 170", and would also be perceived as status seeking.