Well, if you prefer one gender or set of equipment over another, that might help you pick - if you live in a very homophobic area, and you like men, you may find it easier to pass yourself off as a straight woman than a gay man, for the time being. If your attraction's not so binary, consider whether you love your partners like a man does or more like a woman. If that doesn't narrow anything down, or you're aromantic asexual, well it *is* a cheat, it's not guaranteed to work for everyone.
Consider whether you'd rather be called "uncle" or "aunt" if you're sure you never want kids so you couldn't tell whether you'd rather be a mom or a dad - never know what your relatives might do. Consider that the lines in the men's bathrooms are shorter, but the women's are usually cleaner. Consider that, if you pass now, and change your name, you'll receive all the career benefits that come with being male, with fewer worries than most transguys about people checking for references or documentation with the other name - they'll immediately understand *why* you changed it, and if someone else "she"s you, they'd likely assume the person on the other end mismatched the name and the face unless they clarify with "No, that tall guy with the woman's name".
I'm not even necessarily talking about medical transition, since it sounds like you could get most of what you needed, as far as situations that don't involve taking your clothes off go, with a name change to a unisex or male name, and a "yes, I'm a guy" when people ask. And I suppose a doctor's letter for travel or anywhere else they're going to get picky about the gender matching the presentation, just to be sure. It doesn't work for you, no permanent harm done.
