Unfortunately, I think your voice is one of the big ones.
If people don't hear my voice, but see me, they generally think I'm male. I act male, I wear male clothing, my face is generally somewhat masculine, although in a softer sense. Once they hear my voice they just decide I'm a very unfortunate and/or masculine woman. Your voice will be a big factor in whether or not you pass. But if you want people to treat you as the gender you want to be, it's best to either a) get hormones ASAP or b) tell them to do it. Forget the insecurities. Tell them your name is Kyle, correct them if they get it wrong.