I go with my preferred name. People don't question it or go "But what's your real name?", at least not so I can see it (maybe they talk behind my back a bit, but whatever). I don't pass at all due to weird walking style (fallen arches and broad hips, plus I don't move my arms, so instead of putting the "swing" in the shoulders like most guys, I have to put the "swing" in the hips and it looks exaggerated-girly), high voice, etc. Despite this, people have been very nice when I've told them my preferred name. I started doing it when at a friend's birthday party, the friend knew I was a guy but not the other guests. None of them cared either. Before this happened, I would give out my female name because I was afraid of how people would react (laugh at me, ask me what my real name was, call me nasty things, etc), but now I don't care. If they wanna gawk, they can gawk. If they wanna gossip, they can gossip. I am me and I won't stop being me.