First off let me says almost no one is 100% passable, 100% of the time. Even some
post-op transsexuals get read sometimes.
Body type—While most of us are at the edges of “normal” female height/weight distributions, there are women of equal size. Not many, but they’re out there. I’m 5’10” with broad shoulders, yet I’ve seen women larger than me, both in height and build. So it
takes more work, but body type alone won’t make you unpassable. I go out regularly and don’t get read that much.
The truth is most people are pretty oblivious most of the time, so it’s easier to pass than one might think. Of course it makes a difference when, where and how far away. I’m obviously more passable at 30 feet than 3 feet.
Hair, make-up, clothes, shoes—Gotta distinguish between dressing for pleasure and dressing for going out. Many crossdressers look a bit like teenage girls with “Dynasty” hair. Too much make-up, clothes that are too short and too tight, heel that are too high, big and poofy hair. Look around, women just don’t look like that. On one my mailing lists, we were able to help a girl in only a few days go from literally having people point and laugh at her to blending in with only the occasional read, just by toning down these things.
Even if you’re already doing these things “realistically,” it’s important to keep context in mind. women rarely go to the mall dressed the way they’d go to a nice restaurant and vice versa. Also remember age appropriateness. Women of a certain age who dress like Brittany
Spears look ridiculous and so will you. It doesn’t mean you have to look matronly—after all French women look sexy and stylish no matter what age they are—but you do need to be aware of how women dress at different ages. If you watch “What Not to Wear” that an issue that frequently comes up, so you can get some advice that way.
Movement—Clumping around like a guy will give you away. So will slinking like a runway model. women move differently and there’s a variety of websites that can give you tips. But don’t overdo it. For example, just brushing your thighs together as you walk is enough to give some hip sway without looking like your doing a samba.
Voice—If you interact with people and sound like James Earl Jones, it’s going to give you away. Let’s be honest, developing a credible feminine voice is hard work, even for transsexuals for whom it’s really important. Again there’s sites with info how to do this. Technically, the biggest thing you need to do is get rid of the male ressonance in
your voice and use the tonal variations that women use instead of speaking in a male monotone. You probably also need to raise the pitch of your voice a bit, but not as much as you think. The other half is using words in the way that women use, which is different than how men talk. OTOH, while my voice definitely isn’t credible for extended conversation, it does sound somewhat feminine for brief interactions.
But it’s attitude that counts more than anything else. Often newbies are extremely nervous and people pick up on that and give you a close look. Once you’ve realized getting read isn’t the end of the world, people usually relax and in turn get read less. And at worse if you’re read and you act like you deserve respect, my experience is you’ll usually get it.