Just out of anecdotal observation, is seems to me as if there are more bisexuals and lesbians among the trans women, whereas trans men seem to have about the same proportion of gays and bisexuals as cis men.
Several theories I have is that trans women are more likely to be attracted to women because for some, the male body disgusts them because it reminds them of their own bodies if they're pre-op. Another theory is that the allying of the LGB and T communities makes trans women more likely to be out as bi or lesbian than cis women. This doesn't explain why there doesn't seem to be a higher proportion of gay trans men, though.
Anywho, my sexual orientation is that I am more attracted to androgynous or feminine people than masculine people. In other words, I'm mostly attracted to girls, and if I'm attracted to a guy they tend to have lots of androgynous and/or feminine traits, as opposed to the typical "macho guy".