The sum total of what I believe is the healthiest approach to passabilty was shown in this clip from "My Transsexual Summer." Look to blend. Realize that unless you have extreme surgery and / or good genes and transition at a very young age, it's not happening. But, it's not the end of the world, and you can still have an amazing time.
Be honest, and open, open and positive and people will react positively. It's that simple.
